Columbia  ©nitwit? 
intijeCttpoflmitork 

College  of  iPfjpgtctang  anb  Hmrgeons 
Htforarp 


Digitized  by  the  Internet  Archive 

in  2010  with  funding  from 

Open  Knowledge  Commons 


http://www.archive.org/details/experimentalinquOOdoug 


UH.. 


AN 

EXPERIMENTAL  INQUIRY 

INTO    THE 

FUNCTION  OF  THE  LIVER, 

BOTH  IN  THE  FffiTUS  AND  ADULT; 

IN  WHICH  THE  MOST  POPULAR   DOCTRINES  RESPECTING  THE 
FUNCTION   OF  THIS   ORGAN   ARE   EXAMINED, 
AND  THAT  OF   DR     RUSH  ADOPTED 
AND   VINDICATED. 


ALSO, 

AN  EXPERIMENTAL  INQUIRY 

INTO   THE 

FUNCTION  OF  THE  SPLEEN,  GALL  BLADDER,  PANCREAS,  THYROID 
AND  THYMUS  GLANDS,  AND  CAPSULE  RENALES: 

BEING 

AN  INAUGURAL  DISSERTATION, 

Submitted  to  the  public  examination  of  the  Trustees  and  Professors  of  the 

College  of  Physicians  and  Surgeons  in  the  University  of 

the  State  of  New-York, 

SAMUEL  BARD,  M.  D.  IX.  D.  President, 

FOR    THE    DEGREE    OF    DOCTOR  OF  MEDICINB,   ON  THE  SIXTH  DAY  OF  SAY,   1816& 


BY  LUKE  DOUGLAS,  A.  B. 

Member  of  the  American  iEsculapian  Society. 


Every  theory  founded  on  experiment  and  not  assumed,  is  always  good 
for  as  much  as  it  will  explain.  BusEB; 


NEW-YORK: 

PRINTED  BY  JOHN  FORBES  &  CO, 


78  WALL-STREET.. 

1616, 


TO 

VALENTINE  MOTT,  M.  D. 

Professor  of  the  Principles  and  Operations  of  Surgery  in  the  College  of 

Physicians  and  Surgeons  of  New-York;  Fellow  of  the  Literary 

and  Philosophical  Society,  and  President  of  the  Physico* 

Medical  Society  ofNeWwYorkt 

THIS  TREATISE  IS  INSCRIBED, 

AS    A    TESTIMONY    OF    RESPECT     FOR    YOUR 

UNIFORM    FRIENDSHIP,    VIRTUES    AND 

PROFESSIONAL    ABILITIES, 

BY 

YOUR  SINCERE  FRIEND 
AND  PUPIL, 

THE  AUTHOR. 


INTRODUCTION 


The  human  body  being  a  machine  so  infinitely 
complicated,  that,  although  its  anatomy,  so  far  as 
the  eye  or  glass  can  reach  appears  to  be  under- 
stood, a  part  of  its  physiology,  or  function  of  its 
various  organs  is  still  enveloped  in  profound  dark- 
ness. If  this  knowledge  is  within  the  reach  of  hu- 
man understanding,  the  reason  why  it  is  inexplica- 
ble, may  be  justly  ascribed  to  the  superstition 
which  has  pervaded  all  nations,  till  lately,  respect- 
ing the  cultivation  of  anatomy  and  physiology  by 
dissection.  Indeed,  so  great  was  the  abhorrence 
to  this  only  method  of  obtaining  a  knowledge  of 
the  laws  of  organic  life,  that  martyrs  to  humanity 
have  fallen,  in  daring  to  attempt  it.  And  it  is  to  be 
regretted  that  this  black  superstition  still  exists  in 
many  parts  of  this  enlightened  republic.  But  as 
true  science  and  philosophy  progressed,  supersti- 
tion was  gradually  stript  of  its  tyranny,  and  ana- 
tomy and  physiology  began  to  flourish. 

When  it  is  considered  that  all  our  knowledge  of 
the  healing  art  is  founded  on  these  sciences,  a 


VI 


knowledge  of  them  becomes  indispensable.  For 
health  consists  in  an  easy  and  regular  performance 
of  the  various  actions  proper  to  the  human  body; 
and  disease  a  difficulty  in  performing  those  actions, 
hy  which  weariness  and  pain  is  produced,  till  at 
last  a  total  stoppage  of  them  is  death.  An  attempt 
then  to  practice  the  healing  art,  without  a  know- 
lege  of  these  sublime  sciences,  is  chance,  quack- 
ery, and  absurdity  in  the  extreme.  But  it  is  a  la- 
mentable fact,  (and  one  that  the  eyes  of  the  law 
ought  to  discover)  that  many  do  practice  medicine 
without  this  requisite  knowledge.  Hence  the  de- 
gradation of  the  profession  in  the  eyes  of  many,  ig- 
norant of  natural  knowledge.  Having  been  edu- 
cated in  a  school  that  strongly  inculcates  the  ne- 
cessity of  anatomy  and  physiology,  as  laying  the 
foundation  of  a  medical  education,  it  has  claimed 
not  a  small  share  of  my  attention,  and  will  be  the 
subject  of  this  essay. 

From  the  first  dawnings  of  physiological  science 
to  the  present  day,  authors  have  paid  particular 
attention  to  the  liver,  and  have  been  variously  ex- 
ercising their  ingenuity  to  explain  its  function.  And 
if  we  consider  that  the  adult  liver  is  the  largest 
gland  of  the  whole  body,  and  that  of  the  foetus 
composing  more  than  one  fifth  of  the  whole  mass, 
we  are  not  surprised  that  the  ancients  should  make 
it  the  supreme  director  of  the  animal  system. 
Knowing  of  no  other  vessels  by  which  absorption 
could  take  place  than  the  veins,  they  imagined  they 


vn 

could  see  these  absorbing  the  chyle,  carrying  it 
into  the  liver,  there  to  be  converted  into  blood. 
This  blood  they  imagined  was  immediately  trans- 
mitted by  the  vena  cava  hepaticae  to  the  right  side 
of  the  heart,  and  from  thence  the  veins  carried  it 
to  every  part  of  the  body. 

Previous  to  the  discovery  of  the  circulation  of 
the  blood,  the  absorbents,  or  structure  of  glandular 
bodies,  these  opinions  were  not  surprising.  With 
respect  to  glandular  secretion,  the  older  physio- 
logists, being  deficient  in  anatomy,  and  not  having 
premises  on  which  to  found  a  reasonable  hypothe- 
sis, were  content  with  saying,  that  glands  posses- 
sed an  inherent  power  to  separate  from  the  blood 
the  various  secretions  preexisting  in  it.  When  ana- 
tomical knowledge  became  more  diffused,  recourse 
was  had  to  hypothesis ;  such  as  fermentation,  filtra- 
tion, &c.  the  former  supported  by  Van  Helmont, 
the  latter  by  Borelli  and  others.  These  hypothe- 
ses, resting  on  authority  and  fashion  alone,  soon 
gave  way  to  others  not  less  fallacious.  Secreting 
surfaces  were  supposed  by  Winslow  and  Helvetius, 
to  be  imbued  with  a  fluid,  corresponding  in  pro- 
perties with  that  to  be  secreted;  accordingly  a 
watery  fluid  could  not  pass  through  an  oily  surface, 
&c.  and  vice  versa.  Upon  this  principle  the  dif- 
ference of  serous,  mucous,  and  other  secretions  wag 
founded.  Other  physiologists,  among  whom  was 
Boerhaave,  ascribed  it  to  the  impetus  of  the  blood 
in  the  secreting  organ.     Others  to  the  caliber. 


via 

length  and  convolutions  of  vessels.  While  others, 
disregarding  hypothesis,  ascribed  it  altogether  to 
the  vital  action,  disregarding  essentially  structure 
or  organization.  Secretion  must  undoubtedly  be 
referred  to  vital  action,  but  differently  organized 
bodies  seem  to  be  essential  to  the  different  secre- 
tions, for  we  see  a  simple  canal,  a  convoluted  canal, 
cells,  and  a  simple  surface  all  pouring  out  their 
different  secretions.  Therefore  glandular  struc- 
ture becomes  an  object  of  inquiry. 

No  correct  notions  were  entertained  of  the  in- 
ternal structure  of  glandular  bodies  previous  to  the 
time  of  Malpighi.  His  experiments  and  dissections 
taught  him  to  despise  the  scholastic  learning  of  the 
time,  and  by  anatomical  investigation  to  establish 
doctrines  more  consonant  with  reason  and  true 
philosophy.  Throwing  in  his  injections,  carefully 
dissecting  and  examining  with  the  microscope,  he 
saw  the  arteries,  after  making  various  contortions, 
terminate  into  little  cells  or  follicles,  from  which 
the  excretory  duct  originated.  Ruysch,  although 
in  the  early  part  of  his  life,  was  a  disciple  to  the 
doctrines  of  Malpighi,  yet  from  a  more  attentive 
observation,  was  led  first  to  doubt,  then  to  boldly 
reject  them,  and  from  new  facts  to  establish  a  new 
theory,  which  proselyted  a  large  part  of  the  anato- 
mical world.  Ruysch,  by  pushing  his  injections 
more  minutely  and  successfully,  showed  that  the  ar- 
teries, instead  of  terminating  in  a  follicle,  termina- 
ted in  an  excretory  duct  by  a  continuity  of  canal 


IX 

And  what  Malpighi  called  cells,  were  merely  ves- 
sels convoluted  upon  one  another.  The  great  ce- 
lebrity of  Ruysch  made  his  museum  the  resort  of 
kings,  embassadors,  and  all  the  learned  of  the  age. 
Indeed,  to  such  perfection  did  he  carry  the  art  of 
injecting  and  preparing  the  various  parts  of  the  hu- 
man body,  that  no  one  since  his  time  has  surpas- 
sed him. 

The  theories  of  these  two  great  men  still  divide 
the  anatomical  world,  but  perhaps  the  greater  part 
are  on  the  side  of  Ruysch.  Some  believe  both  to 
be  right,  contending  that  acini  and  penicilli,  exist 
in  the  same  gland.  But  it  must  be  observed  here, 
that  although  glandular  structure  at  present  seems 
to  be  pretty  well  understood,  yet  there  exist  many 
glands  in  the  human  body,  the  function  of  which  are 
still  unknown.  The  brain  and  spinal  marrow  a& 
giving  origin  to  the  nerves  of  sense  and  motion,  seem 
to  hold  the  first  rank  among  glandular  bodies. 
The  salivary  glands  pour  their  saliva  into  the 
mouth,  to  moisten  its  parietes,  and  mix  with  the 
comminuted  aliment,  giving  it  an  easy  passage  into 
the  stomach. 

We  see  the  absorbents  bending  their  courses  to- 
wards the  lymphatic  glands,  to  enter  them  in  order- 
to  undergo  some  necessary  change. 

Arterial  blood  passes  into  the  kidney,  from  which 
the  urine  is  separated.  The  same  blood  goes  to 
the  testicle,  from  which  that  divine  fluid  is  secreted, 
which  alone  can  answer  the  purposes  of  genera- 
tion. B 


The  vena  portae,  instead  of  emptying  its  blood 
into  the  ascending  cava,  pours  it  into  the  liver, 
there  to  be  elaborated  into  bile.  The  function  of 
the  above,  and  many  other  glands  appear  to  be  ob- 
vious. But  when  we  speak  of  the  spleen ;  the 
capsular  renales ;  the  thyroid  and  thymus  glands,  no 
obvious  use  has  yet  been  assigned  to  them.  And 
although  the  enormous  volume  of  the  foetal  liver 
would  seem  to  point  out  its  function,  yet  if  we  ex- 
cept the  theory  of  Doctor  Rush,  nothing  satisfacto- 
ry is  known  of  it.  By  seeing  the  liver  secrete  bile 
after  birth,  authors  were  content  with  ascribing  the 
same  function  to  the  foetal  liver,  although  no  use 
has  been  pointed  out  by  them  for  foetal  bile. 

As  reasoning  from  analogy  without  the  aid  of  ex- 
periment is  vain,  I  was  led  to  see  what  facts  would 
result  from  experimenting  on  the  liver  in  living  ani- 
mals, and  from  these  facts  alone  I  have  attempted 
to  reason. 

Experiment  fairly  and  judiciously  conducted  is 
true,  and  was  equally  so  with  Hippocrates  and 
Galen,  as  with  Malpighi  and  Ruysch.  But  we  are 
often  deceived  in  the  consequences  deduced  from 
the  truest  principles ;  owing,  perhaps,  in  part,  to 
the  weakness  of  human  reason,  and  in  part,  to  pre- 
cipitate judgment.  But  experiment  ought  to  found 
the  basis  of  all  our  reasoning,  however  plausible  it 
might  otherwise  appear.  The  blood  of  the  vena 
portarum  from  its  colour,  and  its  circulation  over 
the  surface  of  the  intestinal  canal,  contiguous  to  the 


xi 


excrementitious  part  of  the  aliment,  was  consider- 
ed as  having  putrescent  properties.  And  on  this 
presumption  alone  was  built  an  hypothesis,  ex- 
plaining the  nature  and  uses  of  the  bile,  which  has 
long  existed,  and  believed  by  some  at  the  present 
day,  merely  from  the  plausibility  of  the  inference. 
Now,  one  single  experiment,  made  by  exposing  the 
blood  of  the  vena  portae  and  arterial  blood  to  the 
same  degree  of  temperature,  to  see  which  would 
putrify  first,  conclusively  confuted  this  doctrine, 
wrhich  had  occupied  hundreds  of  pages  in  physio- 
logical writings.  For  it  was  found  that  the  blood 
of  the  vena  portae  was  less  putrescent  than  arte- 
rial blood.  Reasoning  therefore  from  inference, 
however  plausible,  is  fallacious.  And  although 
reasoning  from  experiment  is  not  always  true,  but 
experiment  per  se  fairly  conducted,  is,  and  will  be 
always  true,  however  fallacious  our  reasoning. 
Hence  the  words  of  that  illustrious  chemist  and 
philosopher,  Lavosier.  "  We  ought  in  every  in- 
stance to  submit  our  reasoning  to  the  test  of  expe- 
riment, and  never  to  search  for  truth  but  by  the 
natural  road  of  experiment  and  observation/' 


OBSERVATIONS 


FUNCTION  OF  THE  LIVER 


HAVING  in  the  introduction  given  a  short  outline  of 
the  history,  fabric  and  action  of  glandular  bodies,  I  now 
proceed  to  examine  the  most  popular  doctrines  on  the 
function  of  that  great  and  important  organ,  the  nature  and 
use  of  the  bile,  and  to  offer  my  own  opinion  as  dictated 
by  experiments  performed  on  living  animals. 

But  previous  to  doing  this,  I  wish  it  to  be  understoods 
that  my  experiments  were  made  with  the  intent  of  esta- 
blishing no  particular  theory.  The  function  of  the  foetal 
liver  still  being  enveloped  in  darkness,  the  nature  and 
uses  of  the  adult  bile,  having  for  these  forty  years  past, 
been  the  source  of  more  learned  physiological  controver- 
sy than  have  existed  of  any  other  fluid  of  the  human 
body;  and  observing  that  many  of  these  theories,  al- 
though learned,  ingenious  and  profound,  did  not  rest  on 
experimental  investigation,  the  only  sure  foundation  on 
which  a  lasting  physiological  monument  can  be  erected, 
T  was  led  to  submit  the  most  popular  theories  to  the  test 


14 

of  experiment,  and  the  facts  resulting  therefrom,  I  design- 
ed to  constitute  the  subject  of  this  thesis,  without  forming 
or  supporting  any  particular  theory.  Indeed,  my  origin- 
al design  was  to  confine  my  experiments  and  remarks  ex-. 
clusively  to  the  foetal  liver,  on  the  supposition  of  its  hav- 
ing a  peculiar  function.  But  after  satisfying  myself  that 
that  organ  carried  on  a  chylopoetic  process,  I  was  led  to 
believe,  that  the  liver  after  birth,  performed  the  same 
function  ;  therefore,  my  inquiries  became  more  general. 
Progressing  farther,  and  finding  experiment  to  accord 
generally  with,  and  substantiate  the  doctrines  delivered 
by  the  celebrated  B,ush  on  that  organ,  I  was  necessarily 
led  to  adopt  and  vindicate  the  theory  of  that  philoso- 
pher. But  the  reader  will  soon  discover,  that  experi- 
ment would  not  allow  me  to  adopt  the  whole  of  this 
theory,  especially  with  respect  to  the  spleen,  gall  blad- 
der, and  other  collateral  opinions  ;  but  agree  with  him 
in  the  main  and  most  essential  parts,  namely  ;  That  the 
fcetal  liver  secretes  chyle  from  the  maternal  blood,  trans- 
mitted to  it  through  the  medium  of  the  placenta,  which 
is  poured  into  the  duodenum  by  the  biliary  ducts  ;  ta- 
ken up  by  the  lacteals ;  conveyed  into  the  circulation  ; 
fitted  and  prepared  to  nourish  and  support  the  tender 
foetus. 

That  neither  the  adult  or  foetal  liver  should  be  consi- 
dered as  exclusively  a  secretory  or  an  excretory  organ, 
but  partaking  of  both,  more  excretory  in  the  former  and 
less  so  in  the  latter. 

That  the  adult  liver  performs  the  same  chylopoetic 
function  as  the  foetal ;  but  in  a  less  degree,  its  product 
being  comparatively  less,  and  a  greater  proportion  of  it 
excrementitious. 

That  the  pancreas  is  an  auxiliary  to  the  liver,  and  its  se- 
cretion necessary  to  complete  the  formation  of  chyle. 


15 

(Whether Doctor  Rush  considered  the  stimulus  of  chymea 
or  bile  necessary  to  excite  the  pancreatic  secretion  or  not, 
I  do  not  know ;  he  has  not  mentioned  it:  but,  I  think  the 
fact  sufficiently  proved  by  my   experiments  on  that  or- 
gan.)    So  far  I  agree  with  the  theory  of  Dr.  Rush,  and 
think  that  it  can  be  corroborated  by  experiment.     But 
with  respect  to  the  gall  bladder,  my  experiments  so  far 
from    corroborating  his  theory,    I  think  prove  it  to  be 
incorrect.     And   I   can   by   no   means    agree   with  him 
with  respect  to  the  function  of  the  spleen.     According 
to  this  theory  it  will  be  evident,  that  two  chylopoetic 
processes  are  constantly   going   on  in  the  human  adult 
system.     The  one  performed  in  the  mouth,  stomach  and 
intestines  by  the  action  of  their  respective  fluids  upon 
the  aliment ;  the  other  performed  ostensibly  by  the  liver 
and  pancreas,  agreeably  to  the  theory  of  Rush,  but  in 
my  opinion  greatly  aided  by  the  spleen,  as  experiment 
will    shortly   show.     It   will  also  be  evident,    that    the 
whole  chylopoetic   process   of   the   foetus  is  performed 
ostensibly  by  the  liver,  without  the  aid  of  the  stomach, 
assisted  according  to  my   views,   less   by   the   pancreas 
and  spleen,  and  more  by  the  thymus  gland  and  capsu- 
lar renales.     After  birth,  the  solution  of  the  aliment  by 
the  action  of  the  saliva,  gastric  and  intestinal  juices  and 
absorbents  upon  it,  may  be  considered  the  primary  or 
imperfect  process,  because  the  chyle  although  absorbed 
and  carried  into  the  circulation,  is  not  sufficiently  ani- 
malized  to  become  pure  blood,  or  to  serve  all  the  pur- 
poses   of    nutrition    and    secretion,    but    requires    the 
second,    or    perfect    process,    to    complete    that    defi- 
ciency. 

As  the  foetal  liver  was  the  first  object  of  inquiry,  I 
deem  it  necessary  to  make  some  remarks,  particularly 
on  that  organ,  before  I  proceed  to  those  of  a  more  gen- 


16 

eral  nature.  The  attentive  physiologist  when  viewing 
the  foetal  liver,  is  struck  with  two  remarkable  circum- 
stances: First — its  immense  volume  when  compared 
with  the  liver  of  the  adult  body,  (composing  more 
than  one  fifth  part  of  the  whole  foetal  mass,  and  only 
about  one  twenty-fifth  of  the  adult.)  This  circumstance 
alone,  if  compared  with  the  other  works  of  nature  that 
has  made  nothing  in  vain,  is  enough  to  convince  him 
that  its  function  is  highly  important;  for  tracing  the  un- 
erring laws  of  nature,  he  sees  her  invariably  guard  against 
unnecessary  redundance.  Those  parts  which  have  no 
office  to  perform  until  after  birth,  are  comparatively 
small ;  and  those  useful  only  to  the  foetus,  are  seen  gra- 
dually to  decrease  after  birth,  and  at  last  disappear. 
This  law  being  equally  manifest  in  the  adult  system, 
and  knowing  that  the  liver  is  also  the  largest  viscus  of 
that  body  ;  and  add  to  this  a  knowledge,  that  this  organ 
obtains  in  all  animals  having  red  blood,  is  necessarily 
urged  to  the  strong  belief,  that  the  liver  is  an  exceed- 
ingly important  organ  both  in  the  foetal  and  adult  eco- 
nomy, but  supremely  so  in  the  former. 

Secondly  ;  he  sees  the  maternal  blood,  destined  for 
foetal  nourishment,  brought  by  the  umbilical  vein, 
through  the  medium  of  the  placenta,  instead  of  going 
directiy  to  the  heart,  and  from  thence  sent  to  every 
part  of  the  body,  as  other  decarbonized  or  arterial  blcod 
is,  to  nourish  it ;  is  poured  first  into  the  liver.  Ob- 
serving this  wonderful  peculiarity,  and  reasoning  from 
analogy,  is  convinced  of  the  importance  of  its  function, 
but  contenting  himself  that  the  use  of  the  bile  after 
birth,  is  sufficiently  explained  and  very  obvious,  and 
knowing,  that  it   is    impossible   for  it   to  perform   the 

\ie  offices  in  the  foetus ;  there  being  no  excrementitious 
uarge,  no  chyme  to  change  and  precipitate,  no  ca- 


17 

thartic  or  antiseptic  wanted,  he  is  forced  to  assign  to  this 
great  viscus,  some  peculiar  function,  different  from  that 
which  he  supposes  it  to  perform  after  birth.  And  my 
experiments  were  first  directed  to  ascertain,  what  this 
function  was. 

On  this  ground  different  uses  have  been  assigned  to  it 
by  different  physiologists;  the  most  popular  of  which 
I  shall  mention. 

It  has  been  said  by  Haller,  the  greatest  physiologist 
of  the  last  century,  to  impede  the  velocity  of  the  blood 
in  the  umbilical  vein  before  it  should  be  poured  into 
the  heart.  He  also  says,  that  it  secretes  bile,  which  is 
bland  and  sweet,  but  says  nothing  of  its  use.  By  as- 
signing a  use  to  the  bill  after  birth  which  it  could  not 
serve  in  the  foetus,  physiologists  were  completely  stag- 
gered with  respect  to  the  function  of  the  foetal  liver  :  in- 
deed so  complete  was  their  embarrassment,  that  vague 
and  even  frivolous  uses  have  been  assigned  to  that  im- 
portant viscus.  This  will  explain  the  reason  why  Haller, 
that  prince  of  physiologists,  should  assign  to  this  viscus, 
a  function,  analogous  to  that  performed  by  the  foramen 
caroticum,  of  the  petrous  portion  of  the  temporal  bone. 
It  appears  to  me  very  strange,  that  the  umbilical  vein, 
after  receiving  its  blood  slowly  and  gradually  from  the 
maternal  part  of  the  placenta,  and  running  sometimes  two 
feet  in  a  contorted  manner,  sometimes  taking  two  or 
three  turns  around  the  neck  of  the  foetus  before  it  arrives 
at  the  liver ;  that  the  impetus  of  the  blood  in  this  vein 
should  be  so  great,  as  to  require  an  organ  equal  in  bulk 
to  one-fifth  of  the  foetus,  to  check  its  progress.  We  need 
not  ask  whether  so  great  a  man  as  Haller,  was  satisfied 
with  this  hypothesis.  As  a  physiological  writer,  it  was 
his  duty  to  say  something,  and  perhaps  nothing  more 
reasonable  was  left  to  be  said,  after  assigning  the  above 

C 


-  18 

uses  to  the  bile.     Throughout  the  whole  treatise  of  Haller 
on  the  liver  and  bile,  it  seems  to  be  evident,  that  he  was 
not  satisfied  with  the  doctrines  which  he  inculcates.     He 
seems  to  think,  that  the  purposes  answered  by  the  secre- 
tion of  bile  in  the  liver  after  birth ;  are  too  degrading  for 
an  organ  of  that  magnitude.     Therefore  he  labours  to  as- 
sign other  uses  to  it ;  such  as,  the  support  of  the  dia^ 
phragm  ;  that  it  pushes  it  up  in  expiration,  receives  its 
contraction  in  inspiration,  so  as  to  compress  the  abdomi- 
nal viscera  in   a  uniform  manner ;  and  that  it  foments, 
assists  and  imparts  heat  to  the  stomach,  &c.     And  of  the 
fcetal  liver,  he  says:    f(  When  I  reflect  that  there  is  no 
bile  required  in  the  foetus,  there  being  no  food  received  ; 
when  again  I  see  that  the  liver  is  of  great  size  in  the 
foetus,  and  not  small  like  the  lungs,  which  are  destined 
to  an  operation  in  the  economy  after  birth  ;  I  cannot  but 
suspect,  that  it  has  some  other  use  in  the  foetus,  than  the 
secretion  of  bile."     Charles   Bell,    whose    physiological 
opinions  stand  deservedly   high,   says  :  "  that  we  must 
look   upon    the   peculiarities   of  the   circulation   of  the 
blood  in   the  liver  of  the  foetus,  as  a  provision  against 
the  secretion  of  stimulating  bile."     This  doctrine  I  am 
totally  at  a  loss  to  understand.     Nature  has  formed  an 
organ  in  the  foetus,  which  is  to  perform  no  function  until 
after  birth  ;  but  this  organ,   instead  of  lying  dormant  in 
the  system,  like  the  stomach,  lungs,  kidneys,  &c.  until 
birth  shall  call  it  into  action,  is  more  than  five  times 
larger  comparatively,  than  the  adult  liver  ;  has  four-fifths 
of  the  blood  destined  to  the  foetal  economy  circulating 
through  its  fabric,  and  all  this  wondrous   organization, 
is   merely   to    prevent  it  from    performing   a   function, 
which  is  to  answer  no  purpose  until  after  birth  :  And 
from   the   time   of  birth,   this  organ  begins    to    lessen, 
until  it  shall  have  acquired  its  due  proportion  in  the 


19 

adult  economy.  Can  any  reflecting  mind  be  satisfied 
with  this  doctrine?  Impossible!  especially  when  he 
reflects,  that  little  stimulating  bile  is  required,  until  the 
infant  shall  be  weaned  from  the  mother's  breast ;  for 
white  the  infant  is  at  the  breast,  the  bile  is  but  little 
stimulating.  This  circumstance  induces  the  idea,  that 
there  is  some  analogy  between  the  function  of  the  foetal 
liver  and  the  mamma  of  the  mother ;  the  product  of  the 
former  being  less  stimulating  than  the  latter.  And  al- 
though the  chemical  analysis  of  foetal  bile  and  human 
milk  is  somewhat  different,  I  know  of  no  two  fluids, 
which  are  more  allied  in  their  sensible  properties. 

It  can  hardly  be  expected,  that  the  saliva  and  gastric 
juice  of  the  infant  immediately  after  birth,  can  act  much 
on  its  aliment ;  the  smallness  and  delicate  texture  of 
the  stomach ;  its  thin  and  tender  parietes,  and  the  mi- 
nuteness of  its  blood  vessels,  prevent  the  opinion.  The 
infant,  then,  after  birth,  receiving  (though  less  refined) 
the  product  of  the  foetal  liver  immediately  from  the 
mother,  has  less  use  for  this  organ  ;  hence  its  immediate 
decrease  after  birth,  and  hence  too  the  smallness  of  the 
foetal  spleen  and  vena  portae. 

Richerand  thinks  that  the  liver  performs  the  same 
function  to  the  foetus  as  the  lungs  do  after  birth  :  that  is, 
to  separate  from  the  blood,  its  superabundant  hydrogen 
and  carbon ;  and  attempts  to  account  for  the  large  size 
of  this  viscus  by  supposing,  that  these  obnoxious  prin- 
ciples are  absorbed  and  retained  in  its  fabric.  Now, 
there  is  nothing  in  the  colour  or  composition  of  this 
viscus  which  leads  to  such  a  conclusion.  I  have  made 
repeated  trials,  but  could  never  discover  any  more 
oileaginous  or  fatty  matter  in  the  foetal,  than  in  the 
adult  liver :  its  structure  being  comparatively  finer, 
more  friable  and  delicate,  perhaps  may  have  led  to  this 


20 

opinion.     It  is  as  minutely  vascular  as  the  adult  liver  ; 
by  injecting  it  with  water,  and  sticking  the  point  of  a 
needle  into  any  part  of  it,  this  fluid  will  exude  ;    there- 
fore, if  these  excrementitious  principles   are  absorbed 
and  retained  by  this  viscus,  they  must  form  a  part  of 
its  organic  structure.     It  seems  to  be  remarkable,  that 
a  gland  should  have  the  function  of  separating  from  the 
blood  a  substance  unfit  for  nourishment,  and  that  this 
very  substance  should  form  the  greatest  part  of  its  de- 
licate fabric,  which  is  as  finely  organized,  as  any  other 
part  of  the  foetus.     This  doctrine  must  lead  to  the  con- 
clusion, that  the  greatest  part  of  the  liver,  is  made  up 
of   a    carbo    oileaginous    mass ;  the    contrary    of  this, 
however,   is  the   fact.     I  know  of  no  fact  tending   to 
prove  this  hypothesis,  and  its  author  has  given  us  none  ; 
therefore  it  stands  merely  as  a  matter  of  opinion.     Since 
finishing  my  experiments  on  the  liver,  and  writing  the 
above,  I   received   a  number  of  the  Edinburgh  Medical 
and    Surgical    Journal    for    January,    1815,    from    the 
Professor  of  Surgery  of  this  College,  in  which  was  con- 
tained an    ingenious  treatise    on    the    function  of  the 
foetal  liver,  by  James  Bryce,  F.  R.  S.  E.  fellow  of  the 
Royal  College  of  Surgeons,  Edinburgh. 

He  supposes,  first — That  the  collapsed  foetal  lungs 
completely  fill  the  cavity  of  the  thorax,  the  muscles 
of  respiration  being  in  a  state  of  relaxation. 

Secondly — That  the  great  size  of  the  foetal  liver, 
depends  on  the  quantity  of  blood  sent  to  it  by  the  um- 
bilical vein,  and  the  distention  of  the  biliary  ducts  by 
viscid  bile.  Admitting  that  no  bile  is  poured  into  the 
intestines  during  the  ftetal  state,  but  the  whole  secreted 
becomes  viscid,  distends  and  remains  in  the  bile  ducts 
until  birth.  Now,  the  two  great  foetal  cavities  being 
completely  filled,  and  the  respiratory  muscles  relaxed, 


m 

he  thinks  it  impossible  for  the  fetus  to  inspire,  unless 
some  diminution  takes  place  in  the  cavity  of  the  abdo- 
men, Jn  order  to  admit  the  contraction  of  the  dia- 
phragm. The  first  contraction  of  the  diaphragm,  causing 
the  first  inspiration,  presses  on  the  liver,  squeezes  out 
this  viscid  bile,  which  is  the  meconium,  by  which  the 
liver  is  lessened.  Shortly  after  the  umbilical  cord  is 
tied  ;  or  the  blood  ceases  to  circulate  in  it  by  the  new 
action  of  respiration ;  the  blood  which  before  went  to 
the  liver,  now  goes  to  the  lungs;  the  consequence  is,  an 
immediate  decrease  of  the  liver,  which  admits  of  a  per- 
manent dilatation  of  the  lungs,  thereby  preventing,  what 
he  calls,  "  the  loss  of  tone  and  debility." 

Thirdly — That  little  or  no  blood  goes  to  the  lungs  by 
the  pulmonary  artery. 

This  doctrine  of  the  function  of  the  foetal  liver,  to 
say  the  least  of  it,  is  very  ingenious,  and  at  first  sight 
appears  to  be  plausible,  but  when  submitted  to  the  test 
of  experiment  and  careful  examination,  it  will  be  found 
hypothetical,  and  unsupported  by  good  logic.  The 
opinion,  that  ail  the  bile  secreted  in  the  foetal  state 
remains  in  the  bile  ducts,  there  becomes  inspissated  me- 
conium, distending  not  only  the  coats  of  the  ducts,  but 
enlarging  the  liver,  I  can  confidently  assert  is  without 
foundation.  I  have  now  before  me  a  number  of  foetal 
animals,  taken  from  the  uterus  before  birth  ;  meconi- 
um is  in  the  intestines.  No  appearance  of  viscid  bile 
in  the  bile  ducts :  but  these  contain  a  little  thin,  pellucid, 
sweet  bile,  with  little  or  no  viscidity.  Even  if  this 
viscid  bile  did  exist  in  the  bile  ducts,  it  would  not 
help  the  above  doctrine ;  for  the  cavity  of  the  abdo- 
men would  not  be  diminished  by  its  expulsion  into  the 
intestines.  The  cavity  of  the  chest  does  not  seem  to 
be  completely  filled  by  the  lungs.   I  can  blow  into  the 


22 

trachea  of  one  of  these  animals  before  me,  considerable 
air  without  distending  either  the  abdomen  or  the  chest, 
sufficient  in  my  opinion,  for  what  our  author  calls,  'a 
permanent  dilatation  of  the  lungs.'  The  diaphragm  is 
natural,  not  at  all  saculated  towards  the  chest,  the  only- 
way  that  this  cavity  can  be  made  smaller  by  the  liver. 
Some  blood  does  go  to  the  lungs  by  the  pulmonary  arte- 
ry, for  blood  is  now  running  from  the  pulmonary  veins 
of  an  animal  that  has  never  breathed.  The  great  size 
of  the  liver  of  these  animals  before  me,  does  not  de* 
pend  on  the  blood  sent  to  it  by  the  umbilical  vein ; 
or  inspissated  bile  in  the  bile  ducts,  as  the  following 
experiment  will  show. 

The  contents  of  a  foetal  liver  being  squeezed  gently 
out,  pipes  were  inserted  into  the  vessels  and  stopped 
perfectly  tight;  the  liver  was  then  immersed  into  a 
vessel  of  water,  and  the  height  of  the  water  accurately 
marked  ;  it  was  then  taken  out  and  injected  as  hard 
as  its  fabric  would  bear,  and  again  immersed  in  the 
same  vessel  of  water:  the  rise  of  the  water  was  too 
small  to  be  mentioned,  or  hardly  perceptible,  it  could 
not  have  exceeded  thirty  grains  in  a  liver  that  weighed 
seventeen  drams :  therefore  the  foetal  liver  cannot  be 
much  diminished  in  volume,  at  the  moment  when  the 
change  of  circulation  takes  place.  The  structure  of  the 
liver  itself,  without  the  aid  of  experiment,  forbids  the 
opinion.  A  section  of  the  liver  shows  all  its  vessels 
with  open  mouths,  the  outer  coats  of  which  are  firmly 
attached  to  its  parenchyma. 

Is  a  diminution  of  the  size  of  the  abdomen  or  liver 
necessary  to  the  longitudinal  enlargement  of  the  tho- 
rax ?  Does  not  the  abdomen  readily  and  easily  adapt 
itself  to  its  contents?  A  man  that  can  eat  five  pounds 
at  a  meal,  feels  little  or  no  inconvenience  from  a  full 


23 

or  an  empty  stomach.  Our  female  aborigines,  know 
nothing  of  bandaging  after  parturition,  and  their  two 
hours  confinement,  shows  what  little  inconvenience  the 
abdomen  suffers,  from  its  great  and  sudden  diminu- 
tion. 

Nor  is  the  pregnant  woman  much  incommoded  by 
the  large  size  of  the  uterus,  in  the  latter  months  of  ges- 
tation. Let  us  admit  for  a  moment,  that  the  liver  di- 
minished greatly  at  the  moment  of  respiration;  the  tho- 
rax of  a  human  foetus  would  be  little  enlarged  by  it : 
for  the  middle  of  the  diaphragm  is  tightly  tied  up- 
ward by  the  mediastinum  ;  it  is  difficult  to  move  it 
either  upward  or  downward  without  laceration  ;  the  en- 
largement, therefore,  would  consist  only  of  the  differ- 
ence between  its  natural  curve,  and  a  straight  line 
drawn  from  its  middle,  to  its  insertion  into  the  margin 
of  the  ribs.  It  is  impossible  for  the  thorax  to  be  en- 
larged in  any  other  way,  by  the  reduction  of  the  liver ; 
for  suppose  it  tends  to  push  the  rib6  more  at  a  right 
angle  with  the  spine,  by  bringing  the  ribs  to  their  na- 
tural situation,  the  thorax  will  be  lessened  in  capacity. 
If  the  liver  were  like  the  lungs,  and  the  diaphragm 
saculated  towards  the  chest,  some  probability  might  be 
attached  to  this  hypothesis;  but  as  the  liver  may  be 
considered  a  solid  gland,  not  susceptible  of  dilatation 
or  contraction,  by  the  fluid  circulating  through  it,  I  see 
not  a  shadow  of  probability,  or  even  plausibility  to  this 
hypothesis ;  but  must  look  upon  it,  as  the  offspring  of 
a  fruitful  imagination,  unsupported  by  experiment,  fact, 
or  good  logic. 

The  facts  which  dictated  to  me  the  theory  of  the 
foetal  liver  here  inculcated  are  the  following.  First.  Its 
great  comparative  volume  :  composing  one-fifth  part  of 
the  whole  foetus,     Second^Fpur-nftas  of  the  blood  des* 


24 

tined  to  nourish  the  foetus,  circulates  through  its  fabric. 
Third — The  sensible  properties  of  the  bile :  being  bland* 
sweet  and  pellucid,  greatly  resembling  the  first  milk 
secreted  by  the  mother.  Fourth — The  quantity  of  bile 
secreted  in  a  given  time :  which  is  at  least  ten  ounces 
in  twenty-four  hours  in  an  animal  weighing  less  than 
three  pounds. 

Fifth— Proof  of  its  being   absorbed  by   the  lacteals. 

Sixth — Proof  that  the  bile  is  pouring  into  the  intes- 
tines in  a  small  but  perpetual  streamlet. 

Previous  to  my  departure  from  Europe  in  the  latter 
part  of  the  year  1815,  for  the  United  States,  I  procured 
a  bitch,  that  would  pup  on  the  passage  for  the  purpose 
of  experiment.  The  duodenum  of  one  of  these  pups  was 
open,  while  the  circulation  was  going  on  in  the  funis 
umbilicalis,  and  the  bile  was  seen  flowing  into  it  in  a 
small  but  perpetual  streamlet,  adhering  to  the  parietes 
of  the  intestine.  I  judged  by  the  quantity  poured  in,  in 
five  minutes,  that  at  least  half  an  ounce  must  have 
been  secreted  in  an  hour,  in  this  small  animal,  weigh- 
ing less  than  three  pounds.  The  absorbents  of  the  mi- 
sentery  could  be  seen  distended  with  white  chyle,  and 
by  the  aid  of  a  microscope,  its  motion  was  observable 
in  these  vessels.  The  meconium  of  this  pup  weighed 
fourteen  drams,  by  which  it  appears,  that  in  four  hours, 
more  bile  is  poured  into  the  intestines  of  a  matured 
foetus,  than  would  compose  the  whole  of  the  meco- 
nium. 

I  am  aware,  that  the  above  experiment  does  not  con- 
clusively prove  the  exact  quantity  of  foetal  bile  secreted 
in  a  given  time ;  neither  is  it  easy  to  say  how  this  can 
be  proved.  But  if  a  rational  man,  sees  a  fluid  running 
into  a  receiver,  in  a  small,  equable  and  perpetual  stream- 
let, a  given  time,  and  compares  this  with  other  artificial 


25 

streamlets,  &c.  it  seems  to  be  impossible  that  he  should 
be  much  deceived,  respecting  the  quantity  secreted. 
But  waving  all  argument  of  this  kind,  and  admitting 
that  only  six  ounces  of  bile,  is  poured  into  the  intes- 
tines of  a  matured  human  foetus  in  twenty-four  hours, 
and  allowing  the  meconium  to  be  four  ounces,  which 
has  been  gathering  during  the  whole  time  of  gestation, 
I  ask,  what  becomes  of  all  this  surplus  bile?  No  other 
answer  can  be  given,  since  the  doctrine  of  transudation 
during  life  is  done  away,  than  that  it  must  be  absorbed. 
Well,  if  absorbed,  and  carried  into  the  circulation,  what 
purpose  does  it  answer?  Is  this  the  course  of  obnoxious 
carbon,  or  other  excrementitious  particles  ?  If  this  is 
the  passage  of  a  fluid  unfit  for  nourishment  in  the 
foetus,  why  not  so  after  birth,  or  in  the  adult  body  ?  I 
know  of  no  good  reason  why  it  should  not.  It  is  a 
common  idea,  since  the  explosion  of  the  theory,  that 
the  foetus  was  nourished  by  the  liquor  amnii,  by  ab- 
sorption, that  the  absorbents,  and  especially  the  lacteals, 
lay  pretty  much  dormant  in  the  foetal  system.  Bloom- 
enbach  expresses  this  as  his  opinion.  But  I  should  like 
to  know  how  these  physiologists  account  for  the  growth, 
nourishment,  and  constant  changes  going  forward  in  the 
foetus,  without  these  vessels.  That  this  opinion  is  found- 
ed in  error,  is  proved,  not  only  by  ocular  demonstra- 
tion, but  by  dissection ;  for  the  thoracic  duct  of  the 
foetus  is  comparatively  larger  than  that  of  the  adult.  In 
the  anatomical  museum  attached  to  the  medical  uni- 
versity in  Dublin,  are  many  preparations  establishing 
this  fact.  And  I  am  convinced  of  it  myself,  by  the  dis- 
section of  a  foetal  dog.  While  observing  this  circum- 
stance in  Dublin,  previous  to  imbibing  my  present 
opinions,  the  idea  occurred  to  me,  tnat  the  foetus  must 

D 


2d 

either  be  nourished  by  the  liquor  amnii,  or  that  some- 
thing must  be  absorbed  from  the  intestinal  canal. 

Many  of  the  best  physiologists  allow  that  the  foetal 
liver  secretes  sweet  bile,  and  pours  it  into  the  duodenum. 
The  quantity  secreted  in  a  given  time,  they  have  not 
told  us.  But  I  believe  that  every  one  will  readily  allow, 
that  the  quantity  of  fluid  secreted  by  this  great  organ, 
during  the  long  period  of  gestation,  will  greatly  exceed 
the  small  quantity  of  meconium  found  in  the  intestines. 
Now,  the  mystery  is,  what  becomes  of  this  excess, 
since  we  know  of  no  other  way  that  it  can  get  out  of 
the  intestines,  than  by  absorption.  Authors  being  com- 
pletely at  a  loss  with  respect  to  the  solution  of  this 
question,  have  here  let  the  matter  rest.  And  no  one 
before  our  countryman  Rush,  has  told  the  world  that 
the  foetal  liver  secretes  chyle,  which  is  absorbed  by 
the  lacteals ;  carried  into  the  circulation  ;  there  becomes 
blood  ;  which  is  destined  to  the  growth  and  nourish- 
ment of  the  foetus.  It  is  to  be  regretted  that  this  phi- 
losopher did  not  support  his  theory  by  direct  experi- 
ment. But  he  having  formed  it  from  his  minute  ac- 
quaintance with  the  laws  governing  the  animal  economy, 
it  gives  us  a  more  sublime  idea  of  his  penetrating  ge- 
nius. I  do  not  mean  to  say  that  all  the  product  of  the 
foetal  liver  is  nutritious  ;  a  very  small  portion  of  it  is 
excrementitious,  and  this  latter  portion  I  believe,  form? 
the  meconium. 


%! 


CONCERNING  THE  LIVER  AFTER  BIRTH, 
AND  ITS  SECRETION, 


Physiologists  are  generally  agreed  in  this — that  the 
liver  after  birth  secretes  cystic  bile.  For  of  all  the 
physiological  and  chemical  writers  that  I  have  examin- 
ed, not  one  can  be  found,  who  has  made  any  experi- 
ments on  the  hepatic  bile,  with  a  view  to  ascertain  its 
chemical  analysis  ;  or  pointed  out  any  but  its  sensible 
properties ;  nor  but  few  who  have  mentioned  the  stri- 
king differences  existing  between  them.  Haller  says3 
that  the  cystic  bile  is  bitter,  and  the  hepatic  sweet,  but 
draws  all  his  conclusions  with  respect  to  its  use  from  the 
former. 

Boerhaave  says,  that  bile  is  properly  of  two  kinds, 
cystic  and  hepatic,  the  former  is  thicker,  darker  colour- 
ed and  more  bitter  than  the  latter,  which  is  sweeter  ? 
thin  and  pellucid,  and  suggests  the  propriety  of  calling 
the  hepatic  bile,  lympha  hepatica.  But  notwithstand- 
ing this,  the  bitter  acrid,  viscid  bile  of  the  gall-bladder, 
forms  the  basis  of  all  his  reasoning* 

Doctor  Saunders  of  London,  who  has  written  a  po- 
pular work  on  the  liver,  made  his  experiments,  and 
drew  all  his  conclusions  from  the  more  concentrated, 
acrid,  green  and  bitter  cystic  bile  of  the  ox,  between 
which,  and  the  human  hepatic  bile  there  is  no  analogy. 
The  result  of  his  inquiries  led  him,  of  course,  to  the 
conclusion,   that   the  bile  was  wholly  excrementitious, 


28 

If  Doctor  Saunders  had  measured  the  difference  between 
the  quantity  of  bile  secreted  in  a  given  time,  and  the 
excrementitious  discharge,  perhaps,  it  would  have  cap- 
sized his  theory. 

Fourcroy  also  confined  his  experiments  to  the  cystic 
ox  bile. 

It  is  to  Thenard  alone,  and  that  very  recently,  that  the 
world  is  indebted,  for  the  first  analysis  of  human  cystic 
bile.  But  in  vain  do  we  look  for  a  chemical  analysis 
of  hepatic  bile,  notwithstanding  the  obvious  difference 
existing  between  them. 

Here  then  are  two  sources  of  error. 

First— In  identifying  human  cystic  bile  with  the  cystic 
bile  of  the  ox. 

Second— In  identifying  cystic  and  hepatic  bile  of  the 
same  animal,  and  supposing  them  to  answer  one,  and  the 
same  purpose  in  the  animal  economy,  when  there  is  but 
little  analogy  between  them.  These  errors,  I  consider, 
as  having  laid  the  foundation  of  all  the  physiological 
controversies,  which  have  existed,  respecting  this  too 
much  degraded  fluid.  The  more  ancient  physicians  seem 
to  have  been  better  acquainted  with  the  difference  exist- 
ing between  cystic  and  hepatic  bile,  than  those  of  the 
present  day.  Revenherst  obtained  the  hepatic  bile  by  an 
experiment  made  on  a  living  dog,  and  says,  that  it  is  di- 
lute, not  much  bitter,  very  different  from  the  bile  in  the 
gall  bladder.  Many  anatomists  before  Boerhaave,  believ- 
ed that  the  gall  bladder  secreted  its  own  bile  ;  so  great  in 
their  opinions  was  the  difference  between  cystic  and 
hepatic  bile. 

As  the  theory  of  Doctor  Saunders  respecting  the  func- 
tion of  the  liver,  and  uses  of  the  bile,  is  perhaps  as  popu- 
lar as  any  other  now  extant,  and  he  considering  the  bile 
t;o  be  altogether  excrementitious,  my  first  experiments 


29 

were  directed,  either  to  approve  or  disprove  this  opinion. 
If  the  bile  be  wholly  excrementitious,  it  follows,  that  it 
must  be  all  evacuated,  together  with  a  portion  of  the  ali- 
ment taken  in  by  the  mouth,  per  antrum.  Now,  if  it  can 
be  proved,  that  the  quantity  of  bile  alone  poured  into  the 
alimentary  canal,  exceeds  the  fcecal  discharge,  this  opin- 
ion, I  think,  must  be  erroneous.  How  far  I  have  succeed- 
ed in  proving  this,  the  following  experiments  will  show. 

Experiment,  to  ascertain  the  quantity  of  bile  secreted 
in  a  given  time.  The  duodenum  of  a  living  dog  was 
opened,  and  a  tube  with  a  small  bladder  appended  to  one 
end  of  it,  was  inserted  into  the  ductus  communis  chole- 
dochus ;  in  two  hours  the  cyst  was  examined,  and  four 
drams  of  bile  wras  found  in  it.  This  dog  weighed  thirty 
pounds  :  allowing  the  human  adult  subject  to  weigh  one 
hundred  and  fifty  pounds,  and  make  weight  the  ratio  of 
our  calculations,  thirty  ounces  of  fluid  will  be  poured 
into  the  intestines  of  a  small  sized  man  in  twenty-four 
hours.  But  if  the  difference  of  weight  of  the  liver  be 
made  the  ratio,  twenty-nine  ounces  and  two  drams  will  be 
the  quantity.  Making  the  calibre  of  the  common  duct 
the  ratio,  thirty-six  ounces  and  four  drams.  Making 
vascularity  the  ratio,  ascertained  by  the  quantity  of  fluid 
that  each  viscus  will  contain,  twenty-eight  ounces  and  six 
drams  will  be  the  quantity.  As  these  varied,  comparative 
calculations  so  nearly  agree,  I  think  it  may  fairly  be  con- 
cluded, that  twenty-nine  ounces  of  bile  is  discharged  from 
the  bile  ducts  of  a  common  sized  man  in  twenty-four 
hours.  Considering  this  experiment  important,  it  was 
repeated  with  nearly  the  same  result.  The  quantity  of 
excrementitious  discharge  from  the  intestinal  canal  wras 
ascertained  by  the  following  experiment.  The  faeces  of 
a  common  sized  healthy  labouring  man,  aged  twenty- 
six  years,  whose  appetite  was  unusually  good,  were  care- 


30 

felly  weighed  after  each  evacuation  for  a  week  together ; 
the  seventh  part  of  which  weighed  five  ounces,  two 
drams.  The  same  experiment  was  made  on  another  man 
twenty-seven  years  pld,  equally  healthy,  but  accustomed 
to  a  studious  and  sedentary  life,  and  perhaps  finer  food, 
and  the  daily  quantity  was  three  ounces,  five  drams.  By 
these  experiments,  it  appears,  that  twenty-nine  ounces  of 
bile  are  poured  into  the  intestinal  canal  in  twenty-four 
hours*  and  but  five  ounces  discharged  per  am\um  in  the 
same  time.  Allowing  three  ounces  of  the  daily  foecal 
discharge  to  be  formed  from  the  aliment  taken  in  by  the 
mouth,  (which  will  be  small,  considering  the  quantity 
and  kind  of  aliment,)  there  will  be  a  daily  excess  of  bile 
in  the  intestines,  over  the  foecal  discharge  per  annum,  of 
twenty-seven  ounces.  If  these  experiments  be  correct, 
do  they  not  conclusively  prove  that  the  bile  is  not  wholly 
excrementitious  ?  And  do  they  not  as  clearly  prove  that 
the  greatest  quantity  of  the  bile  is  absorbed  by  the  lac- 
teals  ? 

Most  of  the  physiologists  who  have  written  within 
the  last  century,  teach,  that  one  important  use  of  the  bile 
is,  to  convert  chyme  into  chyle  by  combining  with  it,  and 
precipitating  its  foecal  particles.  My.  next  experiments 
were  directed  to  corroborate  or  disprove  this  opinion.  If 
it  can  be  proved  that  chyme  or  chyle  is  absorbed  without 
the  aid  of  bile  and  vice  versa,  then  a  union  of  them  is  un- 
necessary to  insure  their  absorption,  or  to  constitute  what 
is  understood  by  chyle. 

Experiment,  to  ascertain  whether  chyme  is  absorbed 
without  the  aid  of  bile.  A  dog  was  kept  starving  twen- 
ty-four hours ;  a  ligature  was  then  passed  round  the  com- 
mon duct ;  the  next  day  it  eat  animal  food  greedily ;  two 
hours  after  this  the  absorbents  of  the  mesentery  were  ex- 
amined,   and  -was-  found  distended    with  chyle.      The 


31 

chyme  was  seen  to  pass  along  the  whole  length  of  the 
jejunum  ;  the  intestine  occasionally  contracting  upon  it, 
and  forcing  it  onward,  by  which  the  most  fluid  or  chylous 
portion  seemed   to  be    pressed  out,  and  adhere  to  the 
parietes  of  the  intestine ;  as  it  passed  along,  the  chyme 
grewr  more  viscid,,  and  when  arrived  at  the  lower  part  of 
the  ileon,  it  pretty  much  lost  its  fluidity.     While  observ- 
ing the  operations  of  nature  in  the  intestines  of  this  living 
animal,  I  conceived  the  opinion,  that  as  the  absorbents 
had  the  power  of  abstracting  the  nutritious  particles  of 
the  chyme  as  it  passed  along,  that  if  a  piece  of  solid  ali- 
ment were  in  this  intestine,  it  would  contract  upon  it, 
so  as  that  the  absorbents  could   abstract  its  nutritious 
juices  without  previous  solution.     I  accordingly  made  the 
experiment  by  introducing  a  piece  of  beef  steak,  weighing 
two  drams,  into  the  jejunum  of  a  cat.     An  oblique  inci- 
sion, half  an  inch  long,  was  made  in  the  gut,  which  was 
afterwards  closed  with  three  sutures,  and  the  ligatures 
cut  close  down  to  the  knot.     The  animal  was  kept  con- 
fined forty-eight  hours,  so  as  to  examine  the  faeces,  but 
no  traces  of  indigested  beef  could  be  discovered  in  therm 
This  animal  has  got  entirely  well,  and  is  now  (two  weeks 
after  the  experiment)  running  about  the  gardens. 

This  experiment  I  deem  important  both  to  physiology 
and  surgery.  To  the  former  it  proves,  that  digestion 
can  be  carried  on  in  the  intestines  without  the  aid  of 
mastication,  saliva,  gastric  juice,  or  bile,  that  these  are 
merely  auxiliaries,  or  solvents,  and  that  digestion  essen- 
tially consists  in  the  power  of  the  absorbents  to  abstract 
the  nutritious,  and  reject  the  excrementitious  parts  of 
the  aliment.  I  have  also  seen  by  experiment,  that  in 
half  an  hour  after  food  was  taken  into  the  stomach  of 
an  animal,  the  absorbents  of  the  stomach  were  distended 
with  white  chyle.    The  opinion^  therefore,  that  perfect 


52 

chyle  is  formed  in  the  intestines  previous  to  absorption, 
is  chimerical.  Will  not  these  phenomena  also  explain 
why  the  properties  of  chyle  are  so  little  understood  ? 
Because  it  never  could  be  obtained  in  a  pure  state.  The 
mixture  of  bile,  therefore,  with  chyme  in  the  duodenum, 
does  not  constitute  chyle.  The  only  experiments  which 
I  know  to  have  been  made  to  ascertain  the  correctness 
of  this  opinion,  are  those  made  by  Doctor  Saunders, 
which  led  him  to  reject  the  doctrine.  If  this  union 
is  necessary,  how  does  ehylification  go  on  in  jaundiced 
persons  ?  If  the  common  duct  of  a  living  animal  be 
obstructed,  chyle  is  absorbed  but  of  too  imperfect  a  na- 
ture for  complete  sanguification,  and  the  animal  in  a 
short  time  dies  from  this  cause.  But  if  the  cystic  duct 
only  is  obstructed,  which  is  generally  the  case  in  jaun- 
dice, ehylification  is  perfect,  but  the  bowels  become 
torpid,  and  impacted  with  indurated  fceces,  which  may 
be  relieved  by  hydrogogue  cathartics.  If  the  cause,  how- 
ever be  not  removed,  unnatural  irritation  will  ultimately 
produce  death  ;  but  it  will  be  brought  on  slowly,  and 
the  patient  may  live  a  long  time.  Another  fact,  in  proof 
of  the  theory  that  chyle  is  not  formed  by  the  mixture 
of  chyme  and  bile,  is,  the  alone  absorption  of  bile, 
proved  by  the  following  experiment : 

A  dog,  having  been  previously  well  fed,  was  kept 
starving  twenty-four  hours ;  the  abdomen  was  then 
opened ;  the  stomach  was  perfectly  empty,  but  the  lac- 
teals  below  the  perforation  of  the  common  duct  into 
the  duodenum,  were  tilled  wita  wnite  chyle. 

The  next  use  of  the  bile,  of  which  we  siiall  speak, 
is  one,  I  believe,  universally  admitted,  namely :  its  lique- 
fying, stimulating  and  cathartic  effect,  by  which  the 
peristaltic  motion  of  the  intestines  is  excited,  and  the 
foeces   eliminated   from  the    intestines.     By  the   ready 


33 

passage    of  chyme  along    the  jejunum,  without  bile,  1 
received  the  impression  that  bile  may  assist  only  by  its 
liquefying  effect,  but  of  the  incorrectness  of  this  opinion, 
I  was  convinced  by  the  following  experiments  on  myself. 
A  dram  of  human  cystic  biie  proved  gently  cathartic,  and 
a  dram  of  that  of  the  ox  much  more   so.     The   cystic 
duct  of  a  living  animal  was  tied  ;  costiveness  was  the 
consequence,  although  the  aliment  was  exclusively  fluid. 
These  experiments,   I  think,   are   sufficient  to  substan- 
tiate its  cathartic  effect ;  but   to  its  antisceptic  proper- 
ties as  particularly   taught  by  Doctor  Saunders,  I  can- 
not subscribe.     Now,  this   author   admits  that    hepatic 
bile  becomes  cystic  by  stagnation  in  a  passive  recepta- 
cle.    Such    being  the  fact,  can  this   change  be  induced 
in  any  other  way  than  by  putrefaction  ?  Admitting  that 
a  part  of  its  water  is  absorbed,  and   that   a   little  mu- 
cus is    mixed  with  it,   (of  which   he  has   no  evidence) 
can  this  account  for   its  acrid,   pungent   bitterness,  not 
before  existing?   Why  are  the   faeces  of  jaundiced  per- 
sons almost  void  of  smell  ?  they    remain  much    longer 
in  the  intestines,  and  when   evacuated  from  it  have  no 
tendency  to  putrefaction.     It  is  a  known  fact,  that  the 
more  yellow  or  dark  coloured  the  fceces  (which  colour 
is  imparted  to  them  by  the  cystic    bile)  the   more  pu- 
trid  they  are.     When    I  tied    the   common  duct  of  the 
animal    to   ascertain    the    alone   absorption    of  chyme, 
three   days  after,  the   fceces  remaining   in  this   animal, 
were  indurated,  earthy,  nearly  without  odour,  and  when 
removed  from  the  intestines,  had  no   more  tendency  to 
putrify  than  an  earth  or  a  metal. 

Physiologists  have  long  sought  for  that  peculiar  prin- 
ciple in  the  blood  of  the  vena  port*,  which  fitted  it 
better  for  the  secretion  of  biie  than  artereal  blood.  Had 
thev  known  that  the  liver  secreted  chvie  as  well  a&J)i]e. 

E 


34 

this  property  would  have  been  manifest ;  for  it  is  very 
evident,  that  a  part  only  of  the  arterial  blood  is  fitted 
for  nutrition ;  after  these  particles  are  given  off,  it  is 
received  into  veins,  no  longer  capable  of  performing  the 
office  of  nutrition,  although,  still  containing  nearly  an 
equal  quantity  of  fibrin,  gelatine,  lymph  and  albumen, 
with  arterial  blood,  and  more  carbon.  In  order,  there- 
fore, to  become  arterial  blood  again,  it  is  as  necessary 
that  the  four  first  should  be  farther  elaborated,  as  it  is 
for  the  latter  to  be  lessened.  For  the  whole  mass  of 
venous  blood  is  unfit  for  nourishment.  Accordingly  the 
lungs  abstract  its  carbon,  and  the  liver  elaborates  the 
remainder,  and  renders  it  fit  for  complete  sanguifica- 
tion. 

The  excess  of  carbon  in  venous  blood,  however  it  may 
be   obtained,   I    think   answers    an   important   purpose. 
Every  chemist  will  allow  that  carbon  is  a  very  power- 
ful   antiseptic  ;  and   the  proneness  of  arterial  blood  to 
putrefaction.     Considering  the  slow  and  equable  motion 
of  venous  blood,  and  the  length  of  time  that  it  remains 
in  the  veins,  such  an  antiseptic  seems  to  be  indispensa- 
ble.    Will   not   carbon  alone  explain  the  reason   why 
venous  blood  is  less  putresent  than  arterial  ?  It  may  be 
asked  why  the  blood  of  the  vena  portae  has  the  prefer- 
ence of  other  venous  blood,  in  the  secretion  of  bile  or 
chyle  ?   This  question,  with  respect  to   that  portion  of 
the  vena  port*  formed  by  the  spleenic  veins,  is  answer- 
ed in   our  observations  on  the  spleen.     Respecting  the 
other  part,  it  may  be  answered,  that  although  no  differ- 
ence  can   be  detected    between  this   and  other  venous 
blood,   it  is   probable,  that   the  mesenteric  arteries,  by 
ramifying   over    the  immense  surface  of   the   intestinal 
canal,  may  be  more   completely   deprived  of  its  nutri- 
tious particles,  and  therefore,  require  the  first  elabora- 


35 

tion.  This  will  be  obvious,  with  respect  to  the  stomach 
and  pancreas  after  secreting  their  respective  fluids. 
And  although  the  doctrine  of  absorption  by  veins  has  at 
present  but  few  advocates,  yet  there  is  no  fact  to  prove 
the  contrary,  but  that  the  mesenteric  veins  may  absorb 
such  particles  of  the  chyle  as  are  too  coarse  to  be  receiv- 
ed by  the  absorbents.  Some  distinguished  physiologists 
were  of  this  opinion.  But  whether  either  of  the  above 
opinions  be  correct  or  not,  it  is  known  that  the  liver  is  al- 
ready the  largest  gland  of  the  human  body,  and  that  it 
receives  as  much  blood  as  it  can  elaborate  :  more  blood 
would  require  a  larger  viscus,  which  would  be  unneces- 
sary, because  the  elaboration  of  the  present  quantity  com- 
pletely serves  the  purpose  for  which  it  is  designed.  Then 
why  not  receive  it  from  the  mesenteric  veins  as  well  as 
others.  By  considering  the  quantity  of  blood  going  to  the 
liver  by  the  vena  portae  (which  is  great)  we  can  easily  dis- 
cover how  the  whole  venous  blood  becomes  ultimately 
elaborated.  Suppose  a  family  to  have  a  cistern  contain- 
ing ten  measures  of  water,  one  of  which  being  filtered, 
is  sufficient  to  serve  them  a  day  ;  if  every  day  one  mea- 
sure is  filtered,  and  one  unfiltered  measure  added  to  the 
cistern,  the  family  would  be  supplied,  and  the  cistern 
kept  full  of  sweet  water.  A  larger  filtering-stone  would 
be  unnecessary  to  this  family. 

I  pass  on  now,  to  say  something  of  the  sensible  and 
chemical  differences  existing  between  cystic  and  hepatic 
bile  of  the  same  animal.  Both  kinds  of  bile  having  been 
procured  from  the  same  dogs,  the  cystic  was  of  a  greenish 
or  brownish  yellow  colour,  very  viscid,  not  near  so  bitter 
as  ox  or  fish  bile,  tenacious  so  that  it  \vould  not  drop  from 
a  phial,  ropy,  slightly  acrid  and  nauseous.  While  the  he- 
patic bile  was  of  a  white  slightly  yellowish  colour,  little 
viscid,  slightly  bitter,  little  or  no  tenacity,  of  a   sweet 


36 

mawkish  and  rather  disagreeable  taste,  very  analogous  to 
human  milk  with  a  little  yellow  colouring  matter  in  it. — 
JBy  the  aid  of  heat  and  chemical  reagents  I  endeavour- 
ed to  ascertain  the  properties  of  this  cystic  bile  in  the  fol- 
lowing  way.     On  four   ounces   of   bile   was  poured  an. 
equal  quantity  of  alkohol,  after  standing  forty-eight  hours 
it   was  filtered  through  paper,  a  gluten  was  separated, 
-which,  after  being  dry,   weighed  five  grains ;  this  sub- 
stance resembling  albumen,   or  animal  glue  was  without 
smell  and  nearly  without  taste.     There  ^adhered  to  the 
edges  of  the  paper  a,  brownish   yellow  matter,  in  small 
flakes,  with  a  resinous  matter  adhering  to  it,  having  a 
nauseous  and  acrid  taste;  this  substance  wTas  soluble  in 
water  and  in  alkohol ;  the  latter  abstracts  the  resin  ad- 
hering to  it  and  leaves  it  without  bitterness  ;  in  this  state 
it  has  an  unctuous  feel  and  a  nauseous  taste,  something 
like  tartarized  antimony,  insoluble  in  acids,  and  extreme- 
ly soluble  in  alkalis.     To  the  brown,  yellowish,  transpa- 
rent liquor  that  passed  the  filter,  after  being  evaporated 
nearly  to  the  consistence  of  honey,  distilled  water  was 
added,  no  precipitate  could  be  discovered  after  standing 
twenty-four  hours— the  filter  separated  nothing.     It  was 
then  again  submitted  to  heat ;  very  little  odour  and  none 
of  the  properties  of  bile  could  be  discovered  in  the  vapour 
that  passed  over.     Although  heat  was  very  moderately 
applied,  no  precipitate  took  place  in  any  decree  of  concen- 
tration, although  the  liquor  was  repeatedly  cooled.  When 
the  water  was  driven  oft,  the  residuum  was  of  a  brown 
or  yellowish  black  colour,  as  hard,  and  very  much  resem- 
bling burgundy   pitch,  semi-transparent,   and    a    glossy 
fracture,  having  not  so  much  odour  and  antimonial  taste, 
but  in  oilier  respects  retaining  all  the  sensible  properties 
of  recent  bile  in  a  concentrated  state, 


37 

This  substance,  composing  one  thirtieth  part  of  the 
whole  bile,  was  extremely  and  perfectly  soluble  in  water, 
less  quickly  in  alkohol,  and  still  less  in  alkalis  ;  insoluble 
in  acids  and  in  oils  ;  precipitable  from  its  solutions  by 
acetate  of  lead,  and  more  quickly  and  copiously  by  water 
of  acetated  litharge,  in  soft  white  flakes:  this  precipi- 
tate, although  a  new  compound,  changed  in  colour  and 
rendered  insoluble  ;  still  retained  the  essential  properties 
of  bile.  If  there  be  a  resin  in  bile,  analogous  to  a  vege- 
table resin,  insoluble  in  water  and  dissolved  by  a  pecu- 
liar substance,  not  soda,  which  renders  it  soluble  in  water, 
&c.  I  could  not  obtain  it  in  the  cystic  bile  of  the  dog. 

Equal  parts  of  the  resinous  base  of  bile  were  dissolved 
in  equal  portions  of  water. 

To  the  first  syrup  of  violets  was  added,  which,  after 
standing  some  time,  was  turned  green ;  indicating  the 
presence  of  an  uncombined  alkali,  no  precipitate  took 
place  with  the  nitro  muriate  of  platina,  by  which  I  infer 
that  the  alkali  is  soda. 

To  a  second  was  added  oxalic  acid,  a  slight  precipitate 
indicated  the  presence  of  lime. 

To  a  third  muriate  of  barytes  was  added  ;  a  pretty  co- 
pious precipitate  ensued,  soluble  in  dilute  muriatic  acid, 
without  effervescence.  I  therefore  consider  it  to  be 
phosphate  of  barytes,  because  sulphate  of  barytes  is  inso- 
luble in  dilute  muriatic  acid. 

To  a  fourth  was  added  tincture  of  galls,  then  prussiate 
of  potash,  but  no  trace  of  iron  was  indicated  by  either. 

To  a  fifth  was  added  nitrate  of  silver,  a  very  copious 
white  flaky  precipitate  took  place.  As  the  phosphoric 
acid  exists  in  bile  combined  with  soda  or  lime,  and  as  the 
nitric  acid  of  the  silver  has  a  stronger  affinity  for  the 
soda  than  for  silver,  phosphate  of  silver  might  have  been 
precipitated  by  this  test.     But  by  fusing  this  precipitate 


£8 

with  a  gentle  heat,  lima  cornea  was  formed,  which  indi- 
cated the  presence  of  a  muriate.  No  other  precipitate 
could  be  obtained. 

On  two  ounces  of  hepatic  bile,  obtained  from  dogs, 
was  poured  as  much  concentrated  alcohol ;  after  stand- 
ing forty-eight  hours,  a  gelatinous  substance  was  separa- 
ted by  the  filter,  which  after  desiccation  weighed  eight 
grains :  small  fibrous  flocculi  formed  on  the  filter :  very 
little  yellow,  and  no  resinous  matter  were  observed.  The 
liquor  that  passed  the  filter  was  of  a  white  brownish  co- 
lour, of  a  sweet,  and  at  the  same  time  slightly  bitter  taste. 
This,  being  nearly  four  ounces,  was  evaporated  by  a  gen- 
tle heat  to  about  one  ounce.  At  this  time,  in  the  evening, 
being  called  away,  the  vessel  was  taken  from  the  lamp. 
In  the  morning  there  adhered  to  the  bottom  and  sides  of 
the  vessel  white,  shining,  chrystalline  needles,  of  a  sweet, 
honey-like  taste,  without  smell.  When  viewed  with  a 
microscope,  they  appeared  to  be  parallelopepods,  termi- 
nating in  six-sided  prisms.  I  could  account  for  this 
sweet  salt  in  no  other  way  than  that  it  must  have  been 
insoluble  in  alcohol,  but  required  a  greater  degree  of  con- 
centration, and  a  longer  time  for  its  precipitation  than  al- 
bumen or  yellow  matter,  or  that  these  substances  were  in- 
compatible with  its  precipitation.  On  the  decanted  li- 
quor distilled  water  was  poured,  but  no  precipitate  en- 
sued. It  was  then  evaporated  to  dryness.  The  resi- 
duum was  of  a  greenish,  or  yellowish  white  colour,  but 
in  other  respects  resembling  exactly  the  resinous  base  of 
cystic  bile.  The  quantity  however  was  much  smaller, 
being  only  the  one  hundred  and  fiftieth  part  of  the  whole 
bile,  whereas  that  of  the  cystic  bile,  was  a  thirtieth 
part.  This  residuum  was  treated  with  the  various  tests. 
to  ascertain  its  salts.     Phosphates  of  soda  and  lime  were 


39 

discoverable,  and  muriate  of  soda.     No  uncombined  soda 
or  iron  were  indicated. 

The  above  analysis,  although  imperfect,  owing  to 
the  great  difficulty  of  procuring  the  cystic  bile  of  dogs 
in  sufficient  quantities  for  chemical  experiment,  (for  the 
contents  of  the  gall-bladders  of  seven  large  dogs  only 
afforded  four  ounces)  I  think,  will  sufficiently  point  out 
the  striking  differences  existing  between  cystic  and  he- 
patic bile  of  the  same  animal ;  the  only  design  of  this 
analysis. 


40 


CONCERNING  THE  GALL-BLADDER  AND 
NATURE  OF  ITS  CONTENTS. 


Most  authors,  popular  at  the  present  day,  consider 
the  gall-bladder  as  a  mere  receptacle  of  hepatic  bile ; 
holding  in  reserve  a  sufficient  store  of  this  fluid  against 
the  time  of  need;  filling  by  regurgitation,  when  from 
any  cause  the  passage  of  bile  into  the  duodenum  is  ob- 
structed, or  when  the  stimulus  of  chyme  in  the  duode- 
num is  wanted,  to  draw  forth  the  biliary  secretion. 

Some  suppose  it  to  be  a  mere  passive  receptacle,  dis- 
charged only  by  surrounding  viscera  pressing  upon  it, 
making  it  a  mere  organ  of  chance,  influenced  by  every 
cause  tending  to  press  upon  it. 

Its  viscid,  resinous  and  bitter  properties  are  accounted 
for  by  stagnation,  and  absorption  of  its  aqueous  part. 

Doctor  Rush  believes  it  to  serve  as  a. receptacle  for  re- 
dundant bile  in  the  bile  ducts,  from  whatcause  soeverthis 
may  happen,  thereby  preventing  its  return  upon  the  liver. 
Experiment  has  taught  me  to  differ  from  all  these  opi- 
nions. If  the  gall  bladder  was  merely  a  receptacle  of  the 
hepatic  bile,  receiving  this  fluid  when  its  passage  into  the 
duodenum  is  obstructed,  and  pouring  it  out  again  when 
such  obstruction  is  removed,  why  does  it  not  sometimes 
contain  hepatic  bile?  Why  does  it  always  contain 
that  peculiar  fluid,  cystic  bile?  Why  not  sometimes 
found  empty,  as  in  diminished  secretions  of  bile  ?  Why 
not  surcharged  in  redundant  secretions  or  obstructions. 


41 

with  the  same  kind  of  bile  contained  in  the  hepatic 
duct  ?  Suppose  the  gall-bladder  to  be  empty,  and^  that 
a  gall  stone  should  obstruct  the  passage  of  bile  into  the 
duodenum,  at  the  place  where  the  common  duct  per- 
forates the  intestine.  Now,  if  this  organ  was  a  recep= 
tacle  onty,  beyond  all  contradiction  it  would  now  be 
distended  with  hepatic  bile.  But  this  is  not  the  case, 
as  repeated  experiment  will  show.  The  mere  fact,  if 
duly  considered,  that  the  gall-bladder  always,  under 
every  circumstance  and  condition  of  the  biliary  organs, 
contains  a  peculiar  fluid,  differing  as  much  from  hepa- 
tic bile  as  chyle  does  from  blood,  is  sufficient  proof  in 
my  mind  that  this  organ  is  not  a  receptacle  only,  but 
has  its  own  function  to  perform.  Another  conspicuous 
and  important  fact  rebutting  this  opinion  of  regurgita- 
tion is,  the  valvular  structure  of  the  cystic  duct,  and 
its  peculiar  contorted  situation,  and  termination,  with 
respect  to  the  hepatic  duct ;  which,  I  cannot  look  upon 
in  any  other  light,  than  as  a  provision  against  the  re- 
gurgitation of  hepatic  bile.  A  probe  soon  after  death 
cannot  perforate  it  without  breaking  down  its  valvular 
structure  ;  nor  can  water  be  injected  into  it  from  the 
common  duct  during  life.  After  death  this  can  be  ac- 
complished, though  sometimes  with  difficulty :  so  also 
can  the  veins  and  lymphatics  be  injected,  contrary  to 
the  natural  course  of  their  fluids  after  death,  owing  to 
the  flaccid  state  of  their  valves.  But  independent  of 
these  facts,  will  this  doctrine  bear  candid  criticism  ?  It 
is  said  by  its  supporters  that  the  bile  does  not  flow  in 
a  perpetual  and  equable  current  into  the  duodenum, 
but  is  influenced  altogether  by  the  stimulus  of  chyme. 
When  this  stimulus  is  absent,  the  bile,  instead  of  passing 
onward  into  the  duodenum,  in  which  it  is  not  wanted, 
regurgitates  into   the   gall-bladder  ;  which    serves  as  a 

F 


reservoir,  until  such  time  as  the  stimulus  of  chyme 
shall  call  it  forth.  Now,  every  one  who  has  examined 
the  biliary  organs  will  allow,  that  the  secretion  of  bile 
goes  on  while  any  blood  remains  in  the  system ;  and  in- 
stances have  been  known  of  men  to  go  without  food  a 
■week,  in  which  time  the  liver  must  secrete  at  least 
twelve  pounds  of  bile.  What  a  wondrous  gall-bladder, 
then,  here  must  be  to  contain  this  quantity  of  fluid  ! 
equal  at  least  to  the  stomach  of  a  bullock.  Again,  let 
us  reason  upon  this  economy  in  healthy  men,  who  re- 
ceive regular  food.  Cnyme  is  not  always  passing  the 
duodenum  :  at  these  intervals  the  gall-bladder  has  a 
chance  to  fill.  Suppose  now,  the  gall-bladder  to  be 
filled  with  cystic  bile  ;  the  first  meal  or  chyme  produced 
by  it,  would  draw  a  portion  of  it  out,  and  let  in  a  por- 
tion of  hepatic  bile,  every  meal  after  would  do  the  same. 
This  process,  alternately  continued,  would  at  last  ex- 
haust the  gall-bladder  of  every  drop  of  cystic  bile.  This 
reasoning  may  be  farther  illustrated,  by  supposing  a 
vessel  to  contain  a  gallon  of  wine  ;  every  hour  a  pint 
of  this  wine  is  drawn  out  and  replaced  by  the  same 
quantity  of  water  :  not  many  hours  would  elapse,  before 
unmixed  water  would  be  drawn  off.  Therefore  hepatic 
bile  alone  ought  to  be  found  in  the  gall-bladders  of  all 
healthy  regular  feeders.  But  according  to  this  doctrine 
I  cannot  tell,  under  what  circumstances  cystic  bile 
ought  always  to  be  found.  It  is  impossible  for  a  mo- 
ment to  suppose,  that  hepatic  bile  becomes  cystic  by 
stagnation,  &c.  the  short  time  that  it  remains  in  the 
gall-bladder,  in  those  who  live  regularly.  I  believe  that 
no  absorption  takes  place  from  the  gall-bladder,  unless 
ir.  is  obstructed  or  greatly  distended.  With  equal  pro- 
priety we  may  say,  that  the  aqueous  part  of  the  urine 
is  absorbed  when  that  orsan  is  not    distended.     Does- 


43 

not  the  circumstance  that  the  gall-bladder  always 
contains  its  peculiar  fluid,  except  in  cases  of  obstruction 
or  distention,  prove  that  no  absorption  goes  on  from  it 
in  its  natural  state?  In  fine,  the  idea  that  stagnation 
and  natural  absorption  will  account  for  the  difference 
of  -cystic  and  hepatic  bile,  is  to  me  equally  absurd,  as 
that  entertained  formerly,  by  those  who  supposed  the 
gall-bladder  to  secrete  its  own  bile  from  its  own 
blood. 

But  reasoning  without  the  aid  of  experiment,  that  sole 
and  never-failing  source  of  truth,  is  at  best  mere  plausi- 
bility or  shadow  of  truth  ;  but  experiment  instituted 
only  with  a  view  to  establish  a  preconceived  opinion, 
is  not  much  better  than  analogical  reasoning.  I  now 
proceed  to  offer  my  opinion  respecting  the  function 
of  the  gall-bladder,  as  dictated  by  experiment,  and 
in  this  I  hope,  not  to  be  accused  of  possessing  precon* 
ceived  opinions. 

The  gall-bladder,  in  my  opinion,  has  the  function  of 
secreting  or  separating  from  the  hepatic  bile,  its  bitter, 
resinous,  yellow,  viscid,  or  excrementitious  principles, 
holding  them  in  reserve,  till  the  stimulus  of  chyme  in 
the  duodenum,  calls  for  their  stimulating  and  cathartic 
assistance. 

The  following  facts  led  me  to  this  belief.  First — 
The  gall-bladder  fills  slowly  and  gradually,  and  not  by 
regurgitation.  The  abdomen  of  a  living  dog  was  open- 
ed and  the  contents  of  the  gall-bladder  squeezed  gently 
out,  a  ligature  was  now  passed  round  the  common  duct 
close  to  the  duodenum.  Six  hours  after  the  parts  were 
examined,  the  common  duct  was  greatly  distended 
with  bile,  but  the  gall-bladder  was  only  about  one  third 
full,  and  its  contents  had  the  same  properties  as  the 
cystic   bile  of  a  long   starving  animal.     Thinking  that 


14 

some  obstruction  might  possibly  happen  to  the  cystic 
duct,  the  experiment  was  repeated,  but  with  the  same 
result.  Admitting  these  experiments  to  be  correct,  are 
they  not  conclusive  proof  against  the  regurgitation  of 
hepatic  bile  ?  The  conclusion  appeared  to  me  so  palpa- 
ble, that  I  was  obliged  to  abandon  the  theories  hitherto 
taught  respecting  the  function  of  the  gall-bladder,  more 
especially  that  of  Dr.  Rush,  for  if  the  gall-bladder  serv- 
ed merely  as  a  waste  gate,  or  reservoir  to  the  liver,  to 
shield  it  from  harm  in  case  of  obstruction,  or  redundant 
secretion  of  bile  ;  it  certainly  would  have  been  now 
distended. 

Secondly — It  always  contains  the  same  kind  of  bile, 
which  is  very  different  from  hepatic  bile.  This  fact,  I 
satisfactorily  proved,  not  only  in  the  last  experiment, 
but  by  tasting  both  kinds  of  bile,  of  different  animals, 
under  different  circumstances. 

Thirdly — By  the  valvular  structure  and  very  acute  ter- 
mination of  the  cystic  into  the  hepatic  duct.  Every  ana- 
tomist knows  this  fact. 

Fourthly — The  inability  to  inject  water  into  the  gall 
bladder,  from  the  common  duct  in  a  living  animal. 

Fifthly — The  difficulty  of  introducing  a  probe  into  the 
gall  bladder  from  the  common  duct  after  death. 

Sixthly — When  there  is  no  chyme  in  the  duodenum. 
the  gall  bladder  gradually  fills  and  enlarges.  At  the  same 
thne  hepatic  bile  is  profusely  poured  into  the  intestines. 
A  dog  was  kept  starving  three  days;  the  abdomen  was 
then  opened,  and  the  gall  bladder  was  enlarged  and  dis- 
tended with  bile.  The  duodenum  was  then  opened,  and 
hepatic  bile,  having  only  a  slight  bitterness  was  constant- 
ly flowing  into  it.  By  observing  the  flow  of  hepatic  bile 
into  the  duodenum  under  so  many  circumstances  and 
conditions  of  an  animal  body,  I  feel  myself  warranted  in 


45 


saying  that  the  flow  of  hepatic  bile  into  the  duodenum,  is 
as  constant  as  the  circulation  of  the  blood :  that  chyme 
never  presses  on  the  duodenal  canal  of  the  common  duct 
so  as  to  impede  its  flow  ;  and  that  the  secretion  of  hepatic 
bile  is  not  influenced  by  the  presence  of  chyme  in  the  duo- 
denum. Boerhaave  says,  that  the  gall  bladder  is  always 
distended  with  bile  by  long  fasting,  and  he  has  seen  this 
surprisingly  illustrated  in  swine  that  have  been  kept  se- 
veral days,  designedly,  without  food,  before  being  slain. 
These  facts  I  think  sufficient  to  prove  that  the  stimulus  of 
chyme,  draws  forth  only  cystic  bile.  All  physiologists 
agree  that  it  is  difficult  to  explain  the  manner  in  which 
regurgitation  of  hepatic  bile  into  the  gall  bladder  takes 
place;  and  I  could  mention  may  profound  anatomists 
who  disprove  it  altogether,  but  have  not  room  here. 
Neither  have  I  a  disposition  to  make  quotations,  and  a 
recapitulation  of  the  doctrines  of  others,  with  such  ideas 
and  opinions  as  may  arise  from  them,  answer  in  place  of 
experimental  truths.  An  ingenious  and  fruitful  mind 
will  in  a  few  hours  deduce  a  plausible  hypothesis,  from 
the  knowledge  and  opinions  of  others,  which  experiment 
will  as  soon  overturn.  Doctor  Maclurgh  of  Virginia 
wrote  a  long  and  very  ingenious  treatise  on  the  bile,  and 
founded  his  whole  theory  on  the  putrescent  nature  of  the 
blood  of  the  vena  portae.  Had  he  made  only  one  experi- 
ment he  would  have  found  the  blood  of  the  vena  portae 
less  putrescent  than  other  blood,  and  his  whole  ingenious 
plan  would  have  been  overthrown. 

Such  productions,  although  exalting  mental  ingenuity, 
ought  to  be  looked  upon  as  evils,  tending  more  to  con- 
fuse science,  and  fill  the  world  with  empty  opinions  than 
to  advance  it.  It  is  to  a  minute  knowledge  of  anatomy, 
and  candid  experiment  alone,  that  we  must  look,  for  the 
advancement  of  the  sublime  science  of  physiology. 


46 


CONCERNING  THE  PANCREAS  AND  ITS 
SECRETION. 


The  pancreas  has  been  considered  by  most  physi- 
ologists, as  analogous  to  the  salivary  glands  both  in 
structure  and  secretion.  Although  the  pancreatic  fluid 
has  been  the  subject  of  much  controversy,  especially 
between  Sylvius,  his  followers,  and  opposers,  yet  it  is  a 
fact,  that  little  or  nothing  is  known  of  it.  De  Graaf 
and  Nuck  say,  they  have  gathered  it  in  a  dog  weighing 
ten  pounds,  at  the  rate  of  from  two  to  three  drams,  to 
an  ounce  in  an  hour.  Ruysch  and  Fordyce  have  also 
gathered  it,  but  have  not  told  us  the  quantity  secreted 
in  a  given  time ;  indeed,  it  seems  that  the  quantity  ob- 
tained by  Fordyce  was  so  small,  that  he  could  not  ana- 
lyse it;  yet,  however  strange  as  it  may  appear,  he  has 
told  us  all  that  is  now  known  of  the  properties  of  this 
fluid,  which  are,  that  it  is  colourless  and  slightly  saline. 
Muriate  of  soda  was  obtained  by  evaporation,  and  was 
also  indicated  by  the  nitrate  of  silver.  This  is  trie  extent 
of  our  knowledge  respecting  this  fluid. 

It  is  very  strange,  if  the  pancreatic  fluid  is  to  be  ob- 
tained as  easily  and  abundantly  as  is  represented  by  De 
Graaf,  &c.  that  it  has  not  been  an  object  of  animal  che- 
mistry. Brunner  and  Swaive  say  tnat  it  is  insipid,  and 
Sylvius  declared  it  to  be  acid.  Boerhaave  says,  that  it  is 
neither  saltish,  acid,  nor  alkaline.  Haller  says,  ti;at  it 
is  thin,  watry  and  insipid,  neither  acrid,  nor  alkaline, 
the  quantity   secreted  is  uncertain,  but  thinks  it  great 


47 

from   analogy.     Richerand  says  that  nothing  particular 
is  known  of  the  pancreatic  juice,  and  that  we  are  igno- 
rant of  its   quantity.     Biumenbach   says   that  it  is  pro- 
cured with  difficulty,  and  says  not'  ing  more  of  its  pro- 
perties, than   their   resemblance    to    saliva.     Upon   the 
whole,  the  present  state  of  our  knowledge  with  respect 
to  the  pancreatic  secretion,  may  be  summed  up  in  this 
short  sentence  :    "  the  nature  and  action  of  the  pancre- 
atic fluid,  are  analogous  to  those  of  saliva."     From  ob- 
serving  all    these    contradictory    and   jarring   opinions, 
would  not  an  honest  man  be  inclined  to  doubt  whether 
much  or  any  pure  pancreatic    fluid   has  ever  been   ob- 
tained ?  Although  the  authority  of  De  Graaf  and  Nuck. 
are   respectable,   but   if  it    be  considered   that   others5 
equally  respectable,  have  been  unsuccessful  in  their  at- 
tempts to    obtain    it,  the   undefined  manner   in   which 
they  express  the  result  of  their  experiments ;  the  quan- 
tity   secreted  in  an   hour,  in   an  animal   weighing  ten 
pounds,  and  the  object  which  they  had  in  view  ;  I  am 
forced  to  doubt  it.     They  said,  that  they  obtained  an 
ounce-  in  an  hour  from  an  animal  weighing  ten  pounds; 
at  that  rate  the  pancreas  of  a  common  sized  man  ought 
to  secrete  thirty  pounds  in  twenty-four  hours.     Can  any 
person  believe  this  ?  My  experiments  on  that  organ  may 
perhaps  point  out  some  of  its  peculiarities,   and  may 
explain  the  reason  why  the  properties  of  this  fluid  are 
still  enveloped  in  darkness.     My  own  opinion  is,   that 
the  pancreatic  fluid  serves  to  dilute  both  the  bile  and 
chyme,  and  that  the  stimulus  of  one  of  these,   in  the 
duodenum,  is  necessary  to  excite  its  secretion. 

This  opinion  is  founded  on  the  following  facts.  First, 
The  impossibility  to  obtain  it  by  a  tube  inserted  into  its 
duct. 


48 

It  is  unnecessary  to  detail  the  various  experiments  that 
I  made  to  obtain  the  pancreatic  fluid  ;  they  were  made 
by  inserting  a  tube  with  a  cyst  appended  to  one  end  of  it 
into  the  pancreatic  ducts  of  living  dogs  and  cats  ;  but  no 
fluid  in  either  could  be  obtained.  That  the  tube  was  fair- 
ly into  the  pancreatic  duct  of  each  of  these  animals,  there 
can  be  no  doubt ;  for  the  pancreatic  duct  in  all  the  quad- 
rupeds which  I  have  examined,  opens  into  the  duodenum 
from  one  to  two  inches  below  the  common  duct,  by  a 
large  and  protuberant  mouth  ;  so  that  a  tube  is  as  easily 
inserted  into  this  as  into  the  common  duct.  If  no  fluid 
can  be  obtained  from  the  pancreas  by  a  tube  inserted  into 
its  duct,  and  none  can  be  seen  flowing  into  an  empty  duo- 
denum, how  can  the  nature  and  use  of  the  pancreatic 
fluid  be  known  ?  When  chyme  was  in  the  duodenum, so 
soon  as  I  removed  it,  or  kept  it  stationary,  I  could  disco- 
ver no  secretion  ;  the  same  was  the  case  with  bile  ;  there- 
fore I  infer  that  it  dilutes  both  chyme  and  bile  ;  for  the 
little  that  I  could  squeeze  out  of  the  duct  appeared  to  be 
insipid  and  very  dilute.  By  the  termination  of  the  pan- 
creatic into  the  common  duct  in  man,  there  is  more  rea- 
son to  believe  that  it  acts  more  essentially  on  the  bile,  be- 
ing poured  directly  upon  it.  But  even  in  man,  the  pancre- 
atic duct  does  not  always  terminate  into  the  common  bile 
duct.  I  have  generally  found  two  ducts,  one  terminating 
below  the  common  duct,  and  the  other  into  it ;  and  I  have 
in  two  instances  found  the  whole  pancreatic  duct  termi- 
nate into  the  duodenum.  The  circumstance  that  the  pam- 
creatic  duct  terminates  into  the  duodenum  below  the 
common  duct,  I  think  favours  the  idea  that  the  juice  di- 
lutes chyme  as  well  as  bile  ;  for  the  bile,  after  it  has  flow- 
ed through  its  duct,  seems  to  adhere  to  the  parietes  of 
the  intestine,  and  it  is  not  easy  to  explain  how  the  pan- 
creatic fluid  mixes  with  it,  after  passing  over  two  inches 


49 

of  intestine,  before  it  arrives  opposite  to  the  mouth  of  the 
pancreatic  duct. 

Secondly.  The  structure  of  the  pancreas  and  nature 
of  its  fluid,  according  to  the  general  doctrine,  seem  to 
be  analogous  to  the  salivary  glands  and  saliva, 


& 


dO 


OBSERVATIONS  ON  THE  FUNCTION 

OF  THE  SPLEEN, 


It  was  not  my  original  intention  to  have  said  any 
thing  on  the  function  of  this  degraded  organ,  in  this 
dissertation.  But  while  experimenting  on  living  ani- 
mals for  other  purposes,  and  seeing  the  large  quantity 
of  blood  which  this  viscus  poured  into  the  liver,  a 
thought  struck  me  to  remove  it,  and  see  how  it  would 
effect  the  biliary  secretion.  The  result  of  this  experi- 
ment at  once  dictated  to  me  the  function  of  this  organ, 
which  was  soon  strengthened  by  subsequent  experi- 
ments. Although  many  uses  have  been  assigned  to  the 
spleen,  they  are  ail  so  unsatisfactory,  that  the  function 
of  this  organ  is  still  considered  as  being  unknown:  so 
much  so,  that  the  able  professor  of  anatomy  and  physi- 
ology of  this  college,  deemed  it  as  time  mispent  to  re- 
late them.  Instead  therefore  of  relating  the  various  and 
fanciful  theories  respecting  the  function  of  this  organ, 
I  shall  preface  my  remarks  with  the  following  obser- 
vations. 

Most  of  the  organs  of  an  animal  body  seem  to  possess 
a  peculiar,  inherent,  discriminating  power,  not  under 
the  control  of  the  will,  according  to  the  different  offi- 
ces which  they  are  designed  by  nature  to  perform. 
This  faculty  is  peculiarly  exemplified  in  the  senses,  but 
other  organs  seem  also  to  possess  it.  The  pylorus,  like 
a  watchman,  admits  the  digested,  and  rejects  the  indi- 


51 

gested  food.  The  kidney  seems  to  have  the  faculty  of 
selecting  such  blood  as  contain  more  abundantly  the 
constituents  of  the  urine  ;  for  without  this  faculty,  it 
seems  to  me  impossible  to  account  for  the  quick  and 
copious  secretion  of  urine,  immediately  after  drinking 
acidulous  or  diuretic  liquors;  unless  there  be  a  direct 
communication  from  the  stomach  to  the  kidney.  The 
quantity  of  fluid  secreted  by  the  salivary  glands  during 
mastication,  compared  with  that  during  sleep,  or  fasting, 
is  so  great,  that,  considering  the  size  of  the  glands,  it 
seems  impossible  to  account  for  it  on  any  other  prin- 
ciple. 

The  same  reasoning  will  apply  to  the  pancreas,  the 
lacteals,  and  various  other  parts  of  an  animal  body. 
But  this  faculty  seems  to  be  imparted  to  the  spleen  in 
a  singular  and  striking  manner.  For  I  consider  the  spleen, 
as  having  the  function  to  select  imperfect  blood  from 
the  arterial  system,  more  abundantly  loaded  with  the 
constituents  of  the  green  and  bitter  principles  contained 
in  cystic  bile.  How  far  I  am  warranted  in  assigning 
this  function  to  the  spleen,  the  following  experiments 
will  show. 

The  spleen  of  a  living  dog  was  carefully  removed 
with  little  or  no  haemorrhage  :  the  contents  of  the  gall- 
bladder was  next  squeezed  out ;  the  duodenum  was  then 
opened,  and  a  tube  inserted  into  the  common  duct ; 
four  hours  after  it  was  examined,  and  four  drams  of 
fluid  found  in  it,  having  the  following  properties  :  sweet, 
slightly  acrid  animal-like  taste,  little  or  no  viscidity  ;  of 
a  yellowish  white  colour ;  small  yellowish  white  flakes 
floating  on  its  surface,  resembling  milky  water  a  little 
coloured  with  yellow  matter,  without  odour.  In  fine, 
it  appeared  to  be  as  different  from  other  bile  as  arterial 


o2 

is  from  venous  blood ;  there  seemed  to  be  a   manifest 
imperfection  in  its  formation. 

The  gall-bladder  had  received  in  these  four  hours 
about  a  scruple.  This  bile  compared  with  that  squeezed 
out,  had  very  different  properties ;  the  former  having 
little  or  no  bitterness,  less  odorous,  equally  viscid,  and 
more  opaque  than  the  latter  ;  the  former  being  of  a 
brownish  opaque  colour  ;  the  latter  of  a  yellowish  and 
more  pellucid ;  the  former  having  yellowish  flakes  float- 
ing on  its  surface;  the  latter  none.  But  the  greatest 
manifest  difference  was  that  of  bitterness,  being  hardly 
sensible  in  the  former.  The  weight  of  this  dog  was 
nineteen  pounds  ;  now,  according  to  our  former  calcula- 
tions, had  the  spleen  of  this  animal  been  in,  it  should 
have  secreted  in  four  hours,  five  drams  and  two  scru- 
ples; but  instead  of  this,  only  four  drams  were  secre- 
ted. This  difference  of  secretion  together  with  the  re- 
markable sensible  differences  existing  between  the  two 
rl  uids,  was  proof  sufficient  in  my  mind  to  point  out  the 
important  function  of  the  spleen,  viz.  to  prepare  the 
blood  for  the  secretion  of  natural  bile.  This  experiment 
was  repeated  with  nearly  the  same  result.  Having  pro- 
gressed so  far  in  my  enquiries,  and  having  met  with 
good  encouragement,  I  was  stimulated  to  go  further. 
Wishing  to  know  in  what  manner  the  removal  of  the 
spleen  would  effect  the  system  generally,  the  experi- 
ment was  made.  The  animal  refused  meat  or  drink  and 
on  the  fourth  day  died  ;  having  had  during  this  time  no 
evacuation  per  anum.  The  appearance  of  the  abdomen, 
did  not  seem  to  indicate  death  by  inflammation  alone  ; 
the  mesenteric  glands  were  enlarged,  and  small  balls  of 
yellowish  white  indurated  feces  were  found  in  the  ileon. 
The  absorbents  of  the  mesentery  contained  chyle.  Ex- 
cept inflammation,  I  know  not  what  to  ascribe  the  death 


53 

of  this  animal  to,  except  defective  chylification,  and  a 
torpor  of  the  alimentary  canal.  If  this  experiment 
proves  no  more,  I  think  it  proves  the  importance  of  this 
organ  in  an  animal  body.  Some  argue,  that  the  function 
of  the  spleen  cannot  be  very  important,  because  animals 
may  live  some  time  with  it  removed.  This  argument 
has  no  weight.  Animals  may  live  with  part  of  the  lungs 
removed  ;  the  aorta  tied  ;  a  limb  excised,  and  indeed  the 
most  of  the  brain  removed  ;  but  does  this  argue  their 
little  utility  in  an  animal  body  ?  I  was  next  led  to  as- 
certain what  difference,  if  any,  existed  between  spleenic 
venous  blood,  and  other  venous  blood.  Blood  was 
taken  from  the  splenic  and  jugular  veins  of  the  same  ani- 
mal, an  equal  quantity  of  each  was  set  by  to  separate 
into  its  serum  and  crasimentum  when  this  was  accom- 
plished, the  serum  of  each  was  carefully  separated.  The 
splenic  serum  weighed  thirteen  drams  and  one  scruple; 
the  jugular  weighed  twelve  drams  and  eighteen  grains. 
By  submitting  these  to  heat,  each  yielded  a  proportionate 
quantity  of  albumin.  By  washing  the  crasimentum, 
the  spieenic  blood  contained  less  fibrin. 

Now,  serum,  or  albumin  appears  to  be  the  most  unre- 
fined part  of  the  blood.  It  abounds  most  in  diseased 
and  starved  constitutions.  While  the  healthy  and  vigo- 
rous have  a  greater  proportion  of  crasimentum.  Fibrin 
and  gelatine  seem  to  compose  the  most  refined  parts  of 
an  animal  body,  while  albumin  seems  to  be  more  of  a. 
connecting  medium.  Albumin  is  found  in  nearly  all 
the  excretions  of  diseased  persons,  especially  the  dropsi- 
cal and  diabetic.  In  the  former  disease,  Mr.  Cruickshank 
found  the  urine  so  completely  coagulable  by  heat  and 
acids,  as  to  differ  little  from  the  serum  of  the  blood.  But 
when  dropsy  arose  from  a  morbid  state  of  the  liver,  he 
found    the   urine   not   coagulable,    small   in  quantity ; 


54 

high  coloured,  and  depositing  a  pmk  like  sediment. 
These  facts  very  much  favour  t  Lie  doctrine  here  inculca- 
ted,  both  with  respect  to  the  spleen  and  liver.  The  fluid 
of  dropsies  is  generally  poured  out  by  the  exhalent  arte- 
ries before  being  elaborated  in  the  liver,  and  the  urine  is 
secreted  directly  from  the  arterial  system.  In  this  case, 
the  cause  appears  to  be,  a  redundant  quantity  of  imperfect 
serum  in  the  arterial  system,  causing  a  diseased  action  of 
the  exhalents  ;  in  which  case  its  origin  may  be  looked  for 
in  the  stomach.  But  if  the  liver  is  the  cause  of  this  dis- 
ease, the  blood  will  have  passed  from  the  arterial  to  the 
venous  system,  before  the  cause  acts  upon  it.  The  albu- 
minous portion  of  the  blood  then  seemed  to  have  been 
sufficiently  elaborated  in  that  diseased  organ,  as  not  to  be- 
come extraneous ;  hence  the  fluid  of  dropsies  arising 
from  the  liver  is  not  albuminous.  The  pinklike  sedi- 
ment is  likely  to  be  owing  to  the  imperfect  formation  of 
red  globules.  I  made  several  other  experiments  on  the 
spleen,  but  as  they  had  no  tendency  to  disprove,  and  but 
little  to  corroborate  the  above  theory,  I  deem  it  unneces- 
sary to  mention  them.  But  I  believe  a  priori  that  the 
spleen  may  be  safely  considered  as  auxiliary  to  the  liver 
in  elaborating  imperfect  blood,  and  furnishing  more  abun- 
dantly the  stimulating  and  cathartic  principles  of  cystic 
bile. 

In  giving  this  function  to  the  spleen,  it  seems  to  resem- 
ble that  of  the  placenta,  to  which  its  structure  is  very 
■analogous 


55 


OBSERVATIONS  ON  THE  CAPSULE  RENALES 

AND  THYMUS  GLAND  OF1THE  FCETUS, 

AND  THE  THYROID  GLAND  OF 

THE  ADULT. 


My  inquiries  into  the  function  of  the  spleen,  have  led 
me  to  believe  that  these  organs  perform  an  analogous 
function,  viz.  they  concur  with  the  liver  in  completing 
the  assimilating  process.  Are  not  all  the  vascular  and 
glandular  parts  of  an  animal  body,  except  the  brain  and 
nerves,  and  the  parts  concerned  in  the  preservation  of  the 
species,  devoted  exclusively  to  the  assimilation  and  con- 
veyance of  the  aliment,  by  which  an  animal  is  nourished 
and  supported  ?  What  other  office  is  there  to  perform  ? 
From  the  reception  of  the  aliment  by  the  mouth  after 
birth,  or  by  the  umbilical  vein  in  the  foetus,  we  see  it  un- 
dergoing changes  by  the  different  organs  through  which 
it  passes,  according  to  their  different  functions.  In  the 
mouth  and  stomach,  by  the  action  of  the  saliva  and  gas- 
tic  juice,  an  imperfect  chyle  is  formed.  This  is  taken  up 
by  the  lacteals,  carried  first  through  the  lymphatic  glands 
to  be  modified,  then  is  poured  into  the  circulation,  to  be- 
come pure  blood,  which  alone  is  fit  to  nourish  the  animal. 
But  in  order  to  accomplish  this,  other  important  changes 
are  necessary ;  its  extraneous  parts  must  be  taken  away, 
and  its  coarser  ones  refined.  Its  extraneous  parts  are  ta- 
ken away  by  the  skin,  lungs,  kidnies,  bowels,  &c.  and  I 
believe  its  coarser  parts  are  refined  essentially  by  the  li- 


56 

ver,  and  aided  in  the  human  adult  subject  by  the  spleen, 
thyroid  gland,  and  perhaps  other  glands  having  no  excre- 
tory ducts.  The  thyroid  gland  appears  to  be  convenient- 
ly situated  to  perform  the  office  of  a  refining  organ  to  the 
"blood  going  to  the  brain  ;  its  chief  blood  is  received  by  a 
very  large  branch,  arising  from  the  internal  carotid  artery 
just  above  where  the  common  carotid  bifurcates.  It  is 
reasonable  to  suppose,  that  the  primary  and  most  delicate 
organ  of  the  human  body,  requires  the  finest  blood  for 
its  nourishment.  Here  then,  the  thyroid  gland,  like  a 
watchman,  is  placed,  to  abstract  the  coarser  particles 
and  convey  it  back  again  to  the  venous  system.  The 
thymus  gland  of  quadrupeds  seem  to  perform  an  ana- 
logous function.  But  with  the  foetus  in  utero  it  is  dif- 
ferent; having  no  organs  in  action  to  take  away  the 
extraneous  parts  of  its  aliment,  this  is  done  by  the  mo- 
ther ;  but  the  maternal  blood  is  too  stimulating  and  un- 
refined for  direct  transfusion ;  its  too  stimulating  and 
coarser  particles  must  be  taken  away  before  it  is  fitted 
to  nourish  the  delicate  fabric  of  the  foetus.  For  it  is 
presumed,  that  the  blood  of  the  mother  is  as  unfit  to 
nourish  the  foetus,  as  the  aliment  of  the  mother.  Indeed, 
by  examining  the  laws  of  the  animal  economy,  this  pre- 
sumption is  self-evident.  Why  cannot  the  offspring, 
immediately  after  birth,  receive  the  same  stimulating 
juices  for  its  nourishment,  as  those  contained  in  the  ali- 
ments of  the  mother  ?  The  answer  is  obvious ;  its  de- 
licate organs  are  incapable  to  act  upon  it,  therefore, 
high  excitement,  inflammatory  action,  effusion  and 
death  woidd  be  the  consequence.  Why  is  the  bland 
milk  elaborated  in  the  mammae  of  the  mother,  alone  fit 
to  nourish  the  infant  ?  because,  of  all  other  fluids  it  is 
less  stimulant.  Nature  has  therefore  provided  a  remedy 
against  the  direct  transfusion  of  stimulating   maternal 


57 

blood  to  the  foetus.  The  placenta  and  foetal  liver  are 
this  remedy.  No  fact  is  more  evident,  than  that  the 
arterial  blood  of  the  mother  undergoes  a  striking  change 
in  the  fabric  of  the  placenta  ;  it  goes  to  it  of  a  red  Ver- 
million colour ;  comes  from  it  of  a  dark  venous  colour 
and  more  dilute ;  (very  analogous  to  what  takes  place 
in  the  spleen,  which  according  to  our  doctrine  has  a 
similar  function). 

That  the  foetus  is  nourished  by  the  blood  of  the  mo- 
ther, I  think  there  can  be  no  doubt,  when  it  is  consi- 
dered, that  the  uterine  arterial  vessels  inosculate  with 
those  of  the  maternal  part  of  the  placenta,  and  that 
many  diseases  of  the  mother  are  transmitted  to  the 
foetus  in  utero.  And  that,  this  blood  undergoes  a  ma- 
terial change  in  the  placenta  is  equally  manifest  by  the 
striking  differences  existing  between  mother's  blood, 
and  that  contained  in  the  umbilical  vein.  Therefore  I 
think  it  obvious,  that  the  placenta  performs  a  secern- 
ing function  to  the  arterial  blood  of  the  mother.  The 
foetal  liver  has  now  to  elaborate,  and  convert  this  pla- 
cental blood  into  bland  foetal  nourishment ;  and  as  this 
is  no  small  office  to  perform,  the  foetal  liver  is  necessa- 
rily large.  But  as  a  portion  of  the  placental  blood  pass- 
es immediately  to  the  heart  by  the  ductus  venosus,  there 
remains  still  in  the  foetal  circulation,  a  portion  of  unani- 
maiized  blood,  which  nature  does  not  want  to  carry  out 
of  the  system,  and  which  remains  still  to  be  perfectly 
refined.  Now,  as  the  liver  has  done  its  office  by  elabo- 
rating four-fifths  of  the  blood,  and  the  spleen  and  vena 
portae  being  designed  to  perform  their  offices  after  birth, 
it  may  be  asked,  what  organs  are  there  in  the  foetal  sys- 
tem to  perform  this  important  function. 

A  part  of  the  unrefined  blood,  transmitted  to  the  heart 
by  the  ductus  venosus,  goes  through  the  foramen  ovale. 

H 


58 

and  would  be  sent  in  its  impure  state  to  the  depending 
brain,  had  not  nature  prepared  an  effectual  remedy  in  the 
thymus  gland.  This  gland  very  large  in  the  fetus, 
situated  above  the  heart,  in  the  anterior  mediastinal 
space,  filling  nearly  one  third  of  the  thorax,  and  re- 
ceiving large  quantities  of  blood  from  the  carotid  and 
subclavian  arteries,  is  admirably  situated  to  perform  this 
secerning  function,  with  respect  to  that  portion  of  the 
blood  going  to  the  head.  A  part  of  this  unrefined  blood, 
escapes  by  the  ductus  arteriosus  into  the  descending,  or 
ascending  aorta  of  the  foetus  ;  therefore,  other  secerning 
organs  are  necessary.  But  the  function  of  the  spleen  lay- 
ing pretty  much  dormant  in  the  foetal  system,  because  no 
cystic  bile  is  wanted,  the  capsular  renales  of  the  foetus, 
perform  a  vicarious  function  to  the  spleen  after  birth. 
The  capsular  renales  of  a  foetal  dog  are  much  larger  than 
the  kidnies  themselves,  being  stretched  entirely  across  the 
abdomen.  They  receive  the  principal  part  of  their  blood 
from  the  aorta  itself — some  branches  from  the  emulgents, 
and  pour  their  blood  by  large  veins  into  the  vena  cava 
and  renal  veins.  Now,  could  organs  have  been  better 
situated  and  adapted  to  screen  that  portion  of  the  blood 
above  the  curve  of  the  aorta,  than  the  capsulae  renales. 

If  the  doctrines  here  inculcated  be  correct,  will  they 
not  elevate  the  liver  from  its  before  humble  and  de- 
graded oifice,  and  give  it  a  rank  in  the  animal  economy 
second  to  none  but  the  brain?  that  rank  which  its 
volume  and  omnipresence  assigns  to  it. 

And  will  not  important  advantages  result  from  them, 
in  their  application  to  pathology?  Will  not  this  doctrine 
fully  and  completely  explain  why  diseases  of  the  liver 
alternate  with  those  of  the  stomach  and  vice  versa  ? 
Is  it  not  because  the  stomach  and  liver  perform  vicarious 
offices  ?  Will  not  this  doctrine  fully  and  amply  explain 


59 

why  the  diseases  of  the  liver  are  more  frequent  in  hot 
than  in  cold  climates  ;  in  full  and  high  feeders  than  in 
moderate ;  in  wine  and  dram  drinkers  than  in  the  tem- 
perate ?  Every  author  who  has  writen  on  the  diseases  of 
the  liver  of  warm  climates  telL  us  that  a  diseased  stomacch 
is  one  of  its  invariable  symptoms. 

Doctor  T.  Clark  says,  that  a  diseased  stomach  is  not 
only  the  constant  but  often  the  first  sign  of  a  diseased 
liver.  But  this  reciprocity  of  disease  has  been  attempted 
to  be  explained  by  nervous  connection.  This  nervous 
connection  will  equally  apply  to  all  the  abdominal  vis- 
cera, and  indeed  to  every  part  of  the  human  body. 

Will  not  this  doctrine  also  elevate  the  spleen  from  its 
non-organical  state  and  give  to  it  a  function  equal  if  not 
greater  than  that  of  the  kidney  ?  Other  organs  both  in  the 
foetal  and  adult  state,  equally  necessary  to  the  perfect 
harmony  and  completion  of  an  animal  body,  will  be 
raised  from  their  physiological  graves,  and  claim  a  share 
of  no  small  importance  in  the  animal  economy. 


COLUMBIA   UNIVERSITY   LIBRARIES 

This  book  is  due  on  the  date  indicated  below,  or  at  the 
expiration  of  a  definite  period  after  the  date  of  borrowing,  as 
provided  by  the  library  rules  or  by  special  arrangement  with 
the  Librarian  in  charge. 

DATE  BORROWED 

DATE  DUE 

DATE  BORROWED 

DATE  DUE 

C28(946)MIOO 

CO 

LUMBIA  UNIVERSITY  LIBRAF 

0047999357 

o 

M-6)P  185 


D74 


